《复合材料 Composites》课程教学资源（学习资料）第五章 陶瓷基复合材料_Al2O3-SiC-18

Materials Processing echnology ELSEVIER Journal of Materials Processing Technology 164-165 (2005)924-929 Cutting properties of the Al2 O3+ SiC(w) based tool ceramic reinforced with the pvd and cvd wear resistant coatings Sokovica, J Mikula, L.A. DobrzanskiD,*, J. Kopac a, L. Kosecc P. Panjand,.Madejski,APiech a Faculry of Mechanical Engineering, University of Ljubljana, Askerceva 6, S-1000 Ljubljana, Slovenia b Division of Materials Processing Technology and Computer Techniques in Materials Science, Institute of Engineering Materials d Biomaterials, Silesian University of Technology, ul. Konarskiego 18a. 44-100 Gliwice, Poland NTE Department of Materials and Metallurgy, University of Ljubljana, Askerceva 12, S-1000 Ljubljana, Slovenia Jozef stefan Institute, Amova 39, S-1000 Ljubljana. Slovenia Abstract The paper presents investigation results of tribological properties of the coatings deposited with the PVD and CVd techniques on cutting inserts made from the Al2O3+SiC(w) oxide tool ceramic. Tests were carried out on the multipoint inserts made from the Al2O3+ SiC(w) oxide ceramics, uncoated and coated with gradient, mono-, multilayer and multicomponent hard wear resistant coatings composed of TIN, TICN, TiAIN, TiAISIN and AlO3 layers with PVD and CVD processes. Substrate hardness tests and microhardness tests of the deposited coatings were made on the ultra-micro-hardness tester. It was demonstrated, basing on the technological cutting tests of spheroidal cast putting down onto the tool ceramics the thin anti-wear coatings in the PVD and CVd processes increases their abrasion wear hich has a direct effect on extending the tool edge life. Basing on the roughness parameter Ra of the machined cast iron surfac utting tests, improvement was revealed of the machined material properties, cut with coated oxide ceramics compared to material machined with the uncoated tools C 2005 Elsevier B V. All rights reserved Keywords: Oxide ceramics; Al2O3; SiC; Whiskers; Gradient coatings; Multilayer coating, Multicomponent coatings; PVD; CVD; TEM; SEM; Micro-hardness; Scratch test: Pin-on 1. Introduction additions and the sic whiskers. Whiskers with the following parameters: thickness d=0.1-0.5 um and slenderness ratio Machining productivity and quality of the machined work- /=(5-10)d, are introduced into the tool iece depend, to a great extent, on the properties of tool mate- with whiskers are obtained mostly by the isostatic hot sin- rials. Ceramic materials with high hardness and high strength tering and by the uniaxial hot pressing. The increase of the in the broad range of working temperatures and with low whiskers portion to 15-20% causes increase of the ceramics abrasion wear, with the Al2O3 based ones among them, are strength. Further increase of the Sic whiskers portion dete- used more and more often for cutting tools. The Al2 O3 oxide riorates the mechanical properties because of the increased ceramics, as mentioned by the author of the reviewed thesis, probability of the development of whiskers agglomerates is characteristic of high hardness, compression strength at featuring the cracking propagation source. A factor affect the cutting temperature above 1000C, and the best-com- ing the selection of the optimum portion of the Sic phase in pared to other tool materials-chemical wear resistance; how- the sinter is the decrease of the sinter density along with the ever having high brittleness and low thermal shock resistance. growth of the whiskers portion leading to material hardness These drawbacks are compensated in part by using the Tic deterioration, which in case of the material used for cutting tools, is a significant limitation of possibility of its applica- Corresponding author. Tel: +48 32 2371420, fax: +48 32 2371430 tion. Introducing whisker to the oxide ceramics results in thei E-mail address: Idobrzan(@zmn mt pols gliwice.pl (L.A. Dobrzanski hardness increase, improvement of their crack resistance and 0924-0136/S- see front matter O 2005 Elsevier B V. All rights reserved doi: 10. 1016/j- imatprotec. 2005.02.071

Journal of Materials Processing Technology 164–165 (2005) 924–929 Cutting properties of the Al2O3 + SiC(w) based tool ceramic reinforced with the PVD and CVD wear resistant coatings M. Sokovic´ a, J. Mikuła b, L.A. Dobrzanski ´ b,∗, J. Kopacˇ a, L. Kosecˇ c, P. Panjan d, J. Madejski b, A. Piech b a Faculty of Mechanical Engineering, University of Ljubljana, Aˇskerˇceva 6, SI-1000 Ljubljana, Slovenia b Division of Materials Processing Technology and Computer Techniques in Materials Science, Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, 44-100 Gliwice, Poland c NTF, Department of Materials and Metallurgy, University of Ljubljana, Aˇskerˇceva 12, SI-1000 Ljubljana, Slovenia d Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia Abstract The paper presents investigation results of tribological properties of the coatings deposited with the PVD and CVD techniques on cutting inserts made from the Al2O3 + SiC(w) oxide tool ceramic. Tests were carried out on the multipoint inserts made from the Al2O3 + SiC(w) oxide ceramics, uncoated and coated with gradient, mono-, multilayer and multicomponent hard wear resistant coatings composed of TiN, TiCN, TiAlN, TiAlSiN and Al2O3 layers with PVD and CVD processes. Substrate hardness tests and microhardness tests of the deposited coatings were made on the ultra-micro-hardness tester. It was demonstrated, basing on the technological cutting tests of spheroidal cast iron, that putting down onto the tool ceramics the thin anti-wear coatings in the PVD and CVD processes increases their abrasion wear resistance, which has a direct effect on extending the tool edge life. Basing on the roughness parameter Ra of the machined cast iron surface after the cutting tests, improvement was revealed of the machined material properties, cut with coated oxide ceramics compared to material machined with the uncoated tools. © 2005 Elsevier B.V. All rights reserved. Keywords: Oxide ceramics; Al2O3; SiC; Whiskers; Gradient coatings; Multilayer coating; Multicomponent coatings; PVD; CVD; TEM; SEM; Micro-hardness; Scratch test; Pin-on-disc 1. Introduction Machining productivity and quality of the machined work￾piece depend, to a great extent, on the properties of tool mate￾rials. Ceramic materials with high hardness and high strength in the broad range of working temperatures and with low abrasion wear, with the Al2O3 based ones among them, are used more and more often for cutting tools. The Al2O3 oxide ceramics, as mentioned by the author of the reviewed thesis, is characteristic of high hardness, compression strength at the cutting temperature above 1000 ◦C, and the best – com￾pared to other tool materials – chemical wear resistance; how￾ever having high brittleness and low thermal shock resistance. These drawbacks are compensated in part by using the TiC ∗ Corresponding author. Tel.: +48 32 2371420; fax: +48 32 2371430. E-mail address: ldobrzan@zmn.mt.polsl.gliwice.pl (L.A. Dobrzanski). ´ additions and the SiC whiskers. Whiskers with the following parameters: thickness d = 0.1–0.5
m and slenderness ratio l = (5–10)d, are introduced into the tool ceramics. Ceramics with whiskers are obtained mostly by the isostatic hot sin￾tering and by the uniaxial hot pressing. The increase of the whiskers portion to 15–20% causes increase of the ceramics strength. Further increase of the SiC whiskers portion dete￾riorates the mechanical properties because of the increased probability of the development of whiskers agglomerates, featuring the cracking propagation source. A factor affect￾ing the selection of the optimum portion of the SiC phase in the sinter is the decrease of the sinter density along with the growth of the whiskers portion leading to material hardness deterioration, which in case of the material used for cutting tools, is a significant limitation of possibility of its applica￾tion. Introducing whisker to the oxide ceramics results in their hardness increase, improvement of their crack resistance and 0924-0136/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.jmatprotec.2005.02.071

M. Sokovic et al. /Journal of Materials Processing Technology 164-165(2005)924-929 bending strength. Tools containing the SiC whiskers have the Examinations of coatings' thicknesses were made using life exceeding other tool materials even by 300%, allowing the kalotest"method, consisting in the measurement of the at the same time very high cutting speeds. One of the disad- characteristic dimensions of craters developed on the exam- vantages of the reinforced ceramics is decay of whiskers in ined specimen surface with a coating. The measurements case of machining alloys containing iron, which significantly were made on the device developed in house. In addition, imits its use In connection with the unsatisfactory attempts to verify the obtained results, measurements of the coatings to introduce the SiC whiskers to oxide ceramics and serious were made also on the scanning electron microscope on the mutations in its use, the research is conducted on the pos- fractures perpendicular to their free surfaces sibility of improvement of properties of these materials by The microhardness tests of coatings were made on the employment of the surface layers[ 1-24] SHIMADZU DUH 202 ultra microhardness tester. Test con Due to employment of the physical deposition from the ditions were selected so that the required and comparable test gas phase PVD and chemical deposition from the gas phase results would be obtained for all analyzed coatings. Measure- ments were made at 0.07 N load eliminating influence of the including higher surface hardness of the cutting tools made substrate on the measurement results from the ceramic tool materials as the effective thermal and Adhesion evaluation of the coatings on the inves diffusion barrier is developed on their surface, chip carry inserts was made using the scratch test on the CsEm away parameters are improved, which makes it possible to REVEtEST device, by moving the diamond penetrator along use higher cutting parameters, with the resulting productiv- the examined specimens surface with the gradually in ity improvement and product quality, which results in the creasing load The tests were made with the following pa- reduction of machining time and cost[1-24] rameters: load range 0-100N, load increase rate(dL/dn The goal of this paper has been investigation of prop- 100 N/min, penetrator's travel speed(dx/dt) 10 mm/min, erties of the Al2O3+ SiC(w) based oxide tool ceramics acoustic emission detector's sensitivity AE 1. The critical coated with the anti-wear gradient, mono-, multilayers and load Lc, at which coatings adhesion is lost, was determined multicomponent of the TiN, TiAIN, TIN+ TiAISIN+TiN, basing on the registered values of the acoustic emission TiN+multiaiaiSin+tin and Tin+ TiAISiN+AISiTiN AE types in the cathode arc evaporation CAE-PVD and with the Cutting ability of the investigated materials was deter multilayers of the TiCN+TiN and TiN+ AlO3 types ob- mined basing on the technological continuous cutting tests tained in the chemical deposition from the gas phase Cvd of the KGR-Nl-400 spheroidal cast iron with the hardness proces of about 165 HV. The vb=0.30 mm width of the wear band the surface of the tool used for machining was the cr terion of the cutting edge consumption evaluation. Cutting 2. Experimental procedure tests of the investigated Al2O3+ SiC(w) based tool oxide ce ramics- uncoated and coated- were carried out as the con The investigations were carried out on the multipoint tinuous turning without the use of cutting fluids on the nu inserts made from the Al2O3+ SiC(w) oxide ceramics un- merically controlled MORI SEIKI model SI 153 machine coated, coated in the PVd and CVD processes with thin tool. The following parameters were used in the machining coatings. The inserts made from Al2O3+ TiC were gradient, capability experiments: feed rate f=0. 20 mm/rev, depth of mono-,multilayer and multicomponent coated in the PVd cut ap=2 mm, cutting speed ve=250 m/min. The charac process--cathodic arc evaporation( CAE)and CVD process. ter of the developed failure was evaluated basing on obser Specifications of the investigated materials are presented in vations on the light microscope and on the scanning elec- Table 1 tron microscope. In case of the uncoated tools the test was continued until the wear criterion was reached: however e test period for the coated tools was never shorter than ications of the PVD and CVD coatings put down on the Al203+SiC(w) in case of the uncoated tools, which makes it possible to compare the wear band width VB after reaching the wear criterion by the uncoated test piece. Measurements of the thickness(um) type VB values with the accuracy of up to 0.01 mm were carried PVD out using the Carl Zeiss Jena light microscope at the mag Gradient TiN+ TiAISiN +TIN nification of 14x. photos of the cutting inserts' flank and face at various wear stages were made on LEICA mef4A Multilayer PVD +TiN light microscope at the magnification of 10x, and on the TiN+ TiAISiN VD JEOL JSM-5610 scanning electron microscope using mag + AISiTiN cifications of 95-1100x. The examination results were pre bicomponent TiAIN VD sented as plots of the relationship of the wear band VB on Two layers TiCN+TIN CVD tool flank versus test duration, at the particular experiment Two layers AlO3+ TiN CVD conditions. Investigations of surface roughness of KGR-NI-

M. Sokovi´c et al. / Journal of Materials Processing Technology 164–165 (2005) 924–929 925 bending strength. Tools containing the SiC whiskers have the life exceeding other tool materials even by 300%, allowing at the same time very high cutting speeds. One of the disad￾vantages of the reinforced ceramics is decay of whiskers in case of machining alloys containing iron, which significantly limits its use. In connection with the unsatisfactory attempts to introduce the SiC whiskers to oxide ceramics and serious limitations in its use, the research is conducted on the pos￾sibility of improvement of properties of these materials by employment of the surface layers [1–24]. Due to employment of the physical deposition from the gas phase PVD and chemical deposition from the gas phase processes one can obtain further improvement of properties, including higher surface hardness of the cutting tools made from the ceramic tool materials, as the effective thermal and diffusion barrier is developed on their surface, chip carry away parameters are improved, which makes it possible to use higher cutting parameters, with the resulting productiv￾ity improvement and product quality, which results in the reduction of machining time and cost [1–24]. The goal of this paper has been investigation of prop￾erties of the Al2O3 + SiC(w) based oxide tool ceramics coated with the anti-wear gradient, mono-, multilayers and multicomponent of the TiN, TiAIN, TiN + TiAlSiN + TiN, TiN + multiAiAlSiN + TiN and TiN + TiAlSiN + AlSiTiN types in the cathode arc evaporation CAE-PVD and with the multilayers of the TiCN + TiN and TiN + Al2O3 types ob￾tained in the chemical deposition from the gas phase CVD process. 2. Experimental procedure The investigations were carried out on the multipoint inserts made from the Al2O3 + SiC(w) oxide ceramics un￾coated, coated in the PVD and CVD processes with thin coatings. The inserts made from Al2O3 + TiC were gradient, mono-, multilayer and multicomponent coated in the PVD process—cathodic arc evaporation (CAE) and CVD process. Specifications of the investigated materials are presented in Table 1. Table 1 Specifications of the PVD and CVD coatings put down on the Al2O3 + SiC(w) oxide ceramics Type Composition Coating thickness (
m) Process type Monolayer TiN 0.9 PVD Gradient /multilayer TiN + TiAlSiN + TiN 2.5 PVD Multilayer TiN + multiTiAlSiN + TiN 2.8 PVD Gradient TiN + TiAlSiN + AlSiTiN 2.5 PVD Multicomponent TiAlN 2.8 PVD Two layers TiCN + TiN 2.6 CVD Two layers Al2O3 + TiN 7.9 CVD Examinations of coatings’ thicknesses were made using the “kalotest” method, consisting in the measurement of the characteristic dimensions of craters developed on the exam￾ined specimen surface with a coating. The measurements were made on the device developed in house. In addition, to verify the obtained results, measurements of the coatings were made also on the scanning electron microscope on the fractures perpendicular to their free surfaces. The microhardness tests of coatings were made on the SHIMADZU DUH 202 ultra microhardness tester. Test con￾ditions were selected so that the required and comparable test results would be obtained for all analyzed coatings. Measure￾ments were made at 0.07 N load, eliminating influence of the substrate on the measurement results. Adhesion evaluation of the coatings on the investigated inserts was made using the scratch test on the CSEM REVETEST device, by moving the diamond penetrator along the examined specimen’s surface with the gradually in￾creasing load. The tests were made with the following pa￾rameters: load range 0–100 N, load increase rate (dL/dt) 100 N/min, penetrator’s travel speed (dx/dt) 10 mm/min, acoustic emission detector’s sensitivity AE 1. The critical load Lc, at which coatings’ adhesion is lost, was determined basing on the registered values of the acoustic emission AE. Cutting ability of the investigated materials was deter￾mined basing on the technological continuous cutting tests of the KGR-Nl-400 spheroidal cast iron with the hardness of about 165 HV. The VB = 0.30 mm width of the wear band on the surface of the tool used for machining was the cri￾terion of the cutting edge consumption evaluation. Cutting tests of the investigated Al2O3 + SiC(w) based tool oxide ce￾ramics – uncoated and coated – were carried out as the con￾tinuous turning without the use of cutting fluids on the nu￾merically controlled MORI SEIKI model Sl 153 machine tool. The following parameters were used in the machining capability experiments: feed rate f = 0.20 mm/rev, depth of cut ap = 2 mm, cutting speed vc = 250 m/min. The charac￾ter of the developed failure was evaluated basing on obser￾vations on the light microscope and on the scanning elec￾tron microscope. In case of the uncoated tools the test was continued until the wear criterion was reached; however, the test period for the coated tools was never shorter than in case of the uncoated tools, which makes it possible to compare the wear band width VB after reaching the wear criterion by the uncoated test piece. Measurements of the VB values with the accuracy of up to 0.01 mm were carried out using the Carl Zeiss Jena light microscope at the mag￾nification of 14×. Photos of the cutting inserts’ flank and face at various wear stages were made on LEICA MEF4A light microscope at the magnification of 10×, and on the JEOL JSM-5610 scanning electron microscope using mag￾nifications of 95–1100×. The examination results were pre￾sented as plots of the relationship of the wear band VB on tool flank versus test duration, at the particular experiment conditions. Investigations of surface roughness of KGR-Nl-

M Sokovic et al. /Journal of Materials Processing Technology 164-165 (2005)924-929 Table 2 metallographic observations that the high acoustic emission Comparison of mechanical and functional properties of uncoated and coated levels registered for the TiN TiAlSiN+ AlSiTiN coating Al2O3+ SiC(w) tool ceramics may result from the specific structure of the AIsiTiN layer Process type Microhardness Critical load having many micro-particles on its surface. In that case Lc was HVoo7(MPa) Le (N determined optically. In case of TN+ multiTiAISiN+TIN TIN coating the first coating failure symptoms are the conformal PVD TIN+ TLAISIN+TIN PVD cracks resulting from tension, turning into single spallings TIN+multITIAISiN PVD located at the bottom of the developing crevice and in the +IN coating-crevice contact zone. Chipping and spalling failures TiN+ TiAISiN develop in the central zones of the crevices and at their edges +AStIN in the form of the fine arc-shaped craters. Similar effects can TiAIN D 3370 TICN +TiN CVD be observed at the edges in the ending part of the crevice Al2O3+TiN CVD Single failures are often connected forming bands of the lo- cal coating delamination, not more Semicircles connected with the conformal cracking occur at the crevice bottom at 400 spheroidal cast iron in machinability test were made on the big load force, attesting the fragmentation, local delam device SUrtroNIC 10 TAYLOR-HOBSON ination, and consequent relocation of the torn coating frag ments along with the plastic strain of the substrate by the 3. Discussion of investigation results traveling indenter. In case of other PVD coating damages they gave the abrasive wear character, consisting in abrasion The Al2O3+SiC(w) ceramics microhardness is 1870 MPa of the particular layers, with no delamination and significant and grows significantly after deposition of the PVD and CVD spalling or one-or double-side chipping, and peeling, which coatings, except the TiCN+ TiN coating. The maximum mi- attests( especially in case of the first damage type)to very crohardness of HVo.07=40.2 GPa was observed in case of good adhesion of the particular layers to themselves and to the TiN multiTiAISiN TiN PVD coating deposited onto the very good adhesion to the substrate. In case of the CVD the Al2O3+ SiC(w). ceramics substrate. Over 80%increasing coatings deposited onto the Al2O3+ SiC(w)substrate, the de- of microhardness value is also observed after depositing of lamination was observed at the scratch edge and single-sided TiAIN PVD coating and TiN+ AlO3 CVD coating(Table 2). chipping(Fig. 2) No relationship was found out between the substrate hard- It was found out, basing on the repeated technological ness and hardness of the deposited coating, which confirms turning test of grey cast iron with the Al2O3+ SiC(w) ceram the proper selection of the maximum load Fmax =0.07N to ics, that the tool reaches the vB=0.30 mm wear criterion af- eliminate the influence of the substrate hardness on the mea- ter t=7.8 min cutting time. Time of t=7. 8 min was assumed surement result as the comparative criterion for measurement of the wear The TiN+ TiAlSiN+ TiN coating demonstrates the higl band width for all specimens with the Al2O3+ SiC(w) sub- est critical load value Lc=70N measured by the acous- strate After the assumed machining test duration the small tic emission registration(Fig. 1, Table 2). No sudden in- est cutting tool flank wear band width of VB=.13 mm the TiAIN coating; however, the metallographic observations (Fig 3), and the biggest cutting tool flan CVD coating nake it possible to determine optically the critical load of of VB=0. 28 mm was revealed in case of the TIN PVD coat Lc(opt)=99N. A very high acoustic emission level was reg- ing. It was found out, thanks to the metallographic anal istered for the TiN+ TiAISiN+ AlSiTiN coating nearly from ysis carried out on the scanning electron microscope, that the very beginning of the test. It was found out, basing on the the tribological defect types occurring most often, identified 8642 80100 Fig. 1.(a) Indenter trace with the optical Le load, and(b) scratch test results of the TiN+ TiAIsin+ Tin coating surface deposited on Al2O3+ SiCw) substrate

926 M. Sokovi´c et al. / Journal of Materials Processing Technology 164–165 (2005) 924–929 Table 2 Comparison of mechanical and functional properties of uncoated and coated Al2O3 + SiC(w) tool ceramics Coating Process type Microhardness HV0.07 (MPa) Critical load Lc (N) – – 1870 – TiN PVD 2780 38opt TiN + TiAlSiN + TiN PVD 2480 70 TiN + multiTiAlSiN + TiN PVD 4020 58 TiN + TiAlSiN + AlSiTiN PVD 2380 80opt TiAlN PVD 3370 99opt TiCN + TiN CVD 2270 40 Al2O3 + TiN CVD 3670 18 400 spheroidal cast iron in machinability test were made on device SURTRONIC 10 TAYLOR-HOBSON. 3. Discussion of investigation results The Al2O3 + SiC(w) ceramics microhardness is 1870 MPa and grows significantly after deposition of the PVD and CVD coatings, except the TiCN + TiN coating. The maximum mi￾crohardness of HV0.07 = 40.2 GPa was observed in case of the TiN + multiTiAlSiN + TiN PVD coating deposited onto the Al2O3 + SiC(w). ceramics substrate. Over 80% increasing of microhardness value is also observed after depositing of TiAlN PVD coating and TiN + Al2O3 CVD coating (Table 2). No relationship was found out between the substrate hard￾ness and hardness of the deposited coating, which confirms the proper selection of the maximum load Fmax = 0.07 N to eliminate the influence of the substrate hardness on the mea￾surement result. The TiN + TiAlSiN + TiN coating demonstrates the high￾est critical load value Lc = 70 N measured by the acous￾tic emission registration (Fig. 1, Table 2). No sudden in￾crease of the acoustic emission was registered in case of the TiAlN coating; however, the metallographic observations make it possible to determine optically the critical load of Lc(opt) = 99 N. A very high acoustic emission level was reg￾istered for the TiN + TiAlSiN + AlSiTiN coating nearly from the very beginning of the test. It was found out, basing on the metallographic observations that the high acoustic emission levels registered for the TiN + TiAlSiN + AlSiTiN coating may result from the specific structure of the AlSiTiN layer, having many micro-particles on its surface. In that case Lc was determined optically. In case of TiN + multiTiAlSiN + TiN coating the first coating failure symptoms are the conformal cracks resulting from tension, turning into single spallings located at the bottom of the developing crevice and in the coating-crevice contact zone. Chipping and spalling failures develop in the central zones of the crevices and at their edges in the form of the fine arc-shaped craters. Similar effects can be observed at the edges in the ending part of the crevice. Single failures are often connected forming bands of the lo￾cal coating delamination, not more. Semicircles connected with the conformal cracking occur at the crevice bottom at the big load force, attesting the fragmentation, local delam￾ination, and consequent relocation of the torn coating frag￾ments along with the plastic strain of the substrate by the traveling indenter. In case of other PVD coating damages they gave the abrasive wear character, consisting in abrasion of the particular layers, with no delamination and significant spalling or one- or double-side chipping, and peeling, which attests (especially in case of the first damage type) to very good adhesion of the particular layers to themselves and to the very good adhesion to the substrate. In case of the CVD coatings deposited onto the Al2O3 + SiC(w) substrate, the de￾lamination was observed at the scratch edge and single-sided chipping (Fig. 2). It was found out, basing on the repeated technological turning test of grey cast iron with the Al2O3 + SiC(w) ceram￾ics, that the tool reaches the VB = 0.30 mm wear criterion af￾ter t = 7.8 min cutting time. Time of t = 7.8 min was assumed as the comparative criterion for measurement of the wear band width for all specimens with the Al2O3 + SiC(w) sub￾strate After the assumed machining test duration the small￾est cutting tool flank wear band width of VB = 0.13 mm was revealed in case of the TiN + Al2O3 CVD coating (Fig. 3), and the biggest cutting tool flank wear band width of VB = 0.28 mm was revealed in case of the TiN PVD coat￾ing. It was found out, thanks to the metallographic anal￾ysis carried out on the scanning electron microscope, that the tribological defect types occurring most often, identified Fig. 1. (a) Indenter trace with the optical Lc load, and (b) scratch test results of the TiN + TiAlSiN + TiN coating surface deposited on Al2O3 + SiC(w) substrate

M Sokovic et al. /ournal of Materials Processing Technology 164-165(2005)924-929 100g a)Character of wear of the Al2 O3 SiC(w) sample with TiN+ TiAISiN+ AlSiTIN coating, investigated with SEM after cutting test, and (b) the detail Fig 3. Comparison of the approximated values of the VB wear of the Al2 O3+ SiC(w) based ceramics: uncoated and coated with the CVD TiN+AlzO coating depending on machining time. in the investigated materials are as follows: mechanical de- Table 3 fects and abrasive wear of the tool flank, development of the Comparison of calculated with the least squares method curves of the vB crater on tool face, thermal cracks on tool flank, spalling of the cutting edge, and build-up edge from the chip fragments and CVD coatings, depending on machining time Comparison of the approximated values of the VB wear 0.0007x3-00090x2+00649x of the Al2O3+ SiC(w) based ceramics: uncoated and coated y=0002-0.0035x2+00421x y=0005-0.0013x2+0357x0 with the PVD and CVD coatings, depending on machining TiN+multiTiaISin 0.0001x3-0.0024x2+00369x time is shown in Table 3 +TIN Basing on the roughness tests of the machined material, TiN+ TiAISin y=0008x3-0.0002+0.0287x depending on the cutting period, it was found out that de- +AISiTIN positing the PVD and CVD coatin TiAIN 00005x3+0.00091x2+0.0225x0.9944 gs (exce ept TiN, TiaIN TICN+TIN y=0.000x32-00030x2+0.0455x 0.9964 and TIN+ Al2 O3 coatings) onto the Al2O3+ SiC(w) oxide TiN+Alo y=0.0005-000x2+00184x09779 0.35 y=0007x-0.009×2+9.0649X mm f=0.2 mm/rot R=0.9982 目025V=250mmmk=70° L0.15 y=3E0532-0.00050.0184X R=0,9779 910111213141516 Time tIminI Fig 4.(a) Character of wear of the Al2O3 SiC(w) sample with TIN+ Al2O3 coating, investigated with SEM after cutting test, and (b) the detail of (a)

M. Sokovi´c et al. / Journal of Materials Processing Technology 164–165 (2005) 924–929 927 Fig. 2. (a) Character of wear of the Al2O3 + SiC(w) sample with TiN + TiAlSiN + AlSiTiN coating, investigated with SEM after cutting test, and (b) the detail of (a). Fig. 3. Comparison of the approximated values of the VB wear of the Al2O3 + SiC(w) based ceramics: uncoated and coated with the CVD TiN + Al2O3 coating, depending on machining time. in the investigated materials are as follows: mechanical de￾fects and abrasive wear of the tool flank, development of the crater on tool face, thermal cracks on tool flank, spalling of the cutting edge, and build-up edge from the chip fragments (Fig. 4) Comparison of the approximated values of the VB wear of the Al2O3 + SiC(w) based ceramics: uncoated and coated with the PVD and CVD coatings, depending on machining time is shown in Table 3. Basing on the roughness tests of the machined material, depending on the cutting period, it was found out that de￾positing the PVD and CVD coatings (except TiN, TiAlN and TiN + Al2O3 coatings) onto the Al2O3 + SiC(w) oxide Table 3 Comparison of calculated with the least squares method curves of the VB wear for Al2O3 + SiC(w) based ceramics: uncoated and coated with the PVD and CVD coatings, depending on machining time Coating Regression curve R2 Uncoated y = 0.0007x3 − 0.0090x2 + 0.0649x 0.9982 TiN y = 0.0002x3 − 0.0035x2 + 0.0421x 0.9957 TiN + TiAlSiN + TiN y = 0.00005x3 − 0.0013x2 + 0.0357x 0.9995 TiN + multiTiAlSiN + TiN y = 0.0001x3 − 0.0024x2 + 0.0369x 0.9943 TiN + TiAlSiN + AlSiTiN y = 0.00008x3 − 0.0009x2 + 0.0287x 0.9989 TiAlN y = −0.00005x3 + 0.00091x2 + 0.0225x 0.9944 TiCN + TiN y = 0.0002x3 − 0.0030x2 + 0.0455x 0.9964 TiN + Al2O3 y = 0.00005x3 − 0.0005x2 + 0.0184x 0.9779 Fig. 4. (a) Character of wear of the Al2O3 + SiC(w) sample with TiN + Al2O3 coating, investigated with SEM after cutting test, and (b) the detail of (a)

M. Sokovic et al. /Journal of Materials Processing Technology 164-165(2005 )924-929 Table 4 Comparison of the Ra roughness parameter values of the grey cast iron surface machined with the Al2O3+ SiC(w) based tools: uncoated and coated with the PVD and CVD coatings, depending on machining time Time TIN+TIAISIN TIN+ multi TIAISIN TiN +TiAISIN TAIN TICN+TIN TIN+ Al2 O3 +AISiTIN 1.732.101.47 2.00 1.50 I min 00s 2.17 1.40 1.47 30 33 1.50 50 5min 45 1.73 0000 6 min 00s .57 1.53 1.1 tool ceramics results in decrease of the machined mate- Project"COAT-CUTentitled"New generation PVD coat rial roughness and -the same -improvement of its qual- ings on tools for dry on high speed cutting processes'"be- ity, especially at the final machining process stage. From tween the Government of the Republic of Poland and the all the investigated materials, the minimum roughness of Government of the Republic of Slovenia headed by Prof. Ra=1. 13 um at the final machining stage was revealed in L.A. Dobrzanski and Prof J Kopac Researches were fi- case of the TiN+ multiTiAISiN+ TIN coating deposited onto nanced partially within the framework of the Polish State the Al2O3+ SiC(w) ceramics substrate (Table 4). In case of all Committe for Scientific Research Project KBN Nr 3 T08C coatings the roughness of Ra parameter at the final machining 04726, headed by Dr K. Lukaszkowicz and PBZ-100/4/2004 stage is below 2.5 um so the quality of machined material can headed by Prof. L.A. Dobrzanski be described as h References [1] L.A. Dobrzanski, Fundamentals of Materials Science and Physical The Al2O3+ SiC(w) ceramics microhardness grows signif- Metallurgy. Engineering Materials with the Fundamentals of Mate- icantly after deposition of the PVD and CVD coatings. Over rials Design, WNT, Warszawa, 2002 (in Polish) 2]LA. Dobrzanski, E. Hajduczek, J. Marciniak, R 110% increasing of microhardness value is also observed Physical Metallurgy and Heat Treatment of Tool Materials, WNT after depositing of TiN+ multiTiAISiN+ TIN PVD coating, Warszawa, 1990(in Polish). over 80% increasing of microhardness value is observed af- 3]M. Sokovic, K. Mijanovic, J Mater, Process. Technol. 109(2001) ter depositing of TiAIN PVD coating and TiN+ Al2O3 CVD 181-189 coatings. The TiN+ TiAISiN+ TiN coating demonstrates the (4)J Kopac, M. Bahor,. Sokovic,Int.J.Mach. Tools Manuf.42 highest critical load value Lc=70N measured by the acoustic 5]J. Mikula, Structure and properties of Al203 based on tool oxide emission registration but in case of Tiain coating Le value ceramics with wear resistant PVD and CVD coatings, PhD Thesis, was determined optically and achieved 99 Silesian University of Technology, Faculty of Mechanical Engine ings put down demonstrate good adhesion to the substrate ing, Gliwice, 2004 (in Polish) The tribological defect types occurring most often, identified [6]S. Novak, M. Sokovic, M. Komac, B. Pracek, Vacuum 48(1997) in the investigated materials during the technological cutting 107-112 [7 P Holubar, M. Jilek, M. Sima, Surf. Coat. Technol. 133-134(2000) tests are the mechanical defects and abrasive wear of the tool 145-151 flank, development of the crater on tool face, thermal cracks 8]. Holubar, M. Jilek, M. Sima, P. Holubar, Surf. Coat. Technol on tool flank, spalling of the cutting edge, and build-up edge 19) B. Navinsek, P Panjan, M Cekada, Surf. Coat. Technol. 154(2002) 120-121(1999)184-188 from the chip fragments. Depositing the PVD and Cvdcoat- 203. ings onto the Al2 O3+ SIC(w) oxide tool ceramics results in [10] Grzesik, S. Brol, J. Mater. Process. Technol. 134(2003)265-272 the significant increase of the tool life and in lowering the I1 w. Grzesik, Int J Mach. Tools Manuf. 43(2003)145-150 roughness parameter value for the machined material, and 12]J. Barry, G. Byrne, Wear 247(2001)139-151 finally in improvement of its quality, especially at the final [13] J.D. Bressan, R Hesse, E.M. Silva Jr, Wear 250(2001)561-568 achining process stage 14J. Deng, X. Ai, Tribol. Int. 30(1997)807-813 [15] L.A. Dobrzanski, D. Pakula, E. Hajduczek, J. Mater Process. Tech- nol.157-158(2004)331-340 [16] D. Pakula, L.A. Dobrzanski, K. Golabek, M. Pancielejko, A. Kriz, Acknowledgements J. Mater. Process. Technol. 157-158(2004)388-393 [17A.K. Ghani, I.A. Choudhury, Husni, J Mater. Process. Technol, 127 Investigations were partially realized within the frame- [18] L.A. Dobrzanski, K. Golombek, J. Kopac,M Sokovic, Mater. Sci ork of the Scientific and Technology Cooperation Joint Forum437-438(2003)41-44

928 M. Sokovi´c et al. / Journal of Materials Processing Technology 164–165 (2005) 924–929 Table 4 Comparison of the Ra roughness parameter values of the grey cast iron surface machined with the Al2O3 + SiC(w) based tools: uncoated and coated with the PVD and CVD coatings, depending on machining time Coating Time – TiN TiN +TiAlSiN + TiN TiN + multi TiAlSiN + TiN TiN +TiAlSiN +AlSiTiN TiAlN TiCN + TiN TiN + Al2O3 1.73 2.10 1.47 1.83 1.47 2.00 2.10 1.50 1 min 00 s 1.83 2.17 1.37 1.83 1.47 2.10 1.97 1.40 3 min 15 s 1.73 2.33 1.40 1.73 1.23 2.10 1.67 1.47 4 min 30 s 1.70 2.13 1.33 1.60 1.50 2.30 1.70 1.50 5 min 45 s 1.60 2.20 1.43 1.37 1.73 2.70 1.73 1.57 6 min 00 s 1.60 1.97 1.57 1.33 1.53 2.70 1.73 1.63 7 min 15 s 1.53 1.93 1.37 1.13 1.40 2.43 1.80 2.20 tool ceramics results in decrease of the machined mate￾rial roughness and – the same – improvement of its qual￾ity, especially at the final machining process stage. From all the investigated materials, the minimum roughness of Ra = 1.13
m at the final machining stage was revealed in case of the TiN + multiTiAlSiN + TiN coating deposited onto the Al2O3 + SiC(w) ceramics substrate (Table 4). In case of all coatings the roughness of Ra parameter at the final machining stage is below 2.5
m so the quality of machined material can be described as high. 4. Summary The Al2O3 + SiC(w) ceramics microhardness grows signif￾icantly after deposition of the PVD and CVD coatings. Over 110% increasing of microhardness value is also observed after depositing of TiN + multiTiAlSiN + TiN PVD coating, over 80% increasing of microhardness value is observed af￾ter depositing of TiAlN PVD coating and TiN + Al2O3 CVD coatings. The TiN + TiAlSiN + TiN coating demonstrates the highest critical load value Lc = 70 N measured by the acoustic emission registration but in case of TiAlN coating Lc value was determined optically and achieved 99 N. All the coat￾ings put down demonstrate good adhesion to the substrate. The tribological defect types occurring most often, identified in the investigated materials during the technological cutting tests are the mechanical defects and abrasive wear of the tool flank, development of the crater on tool face, thermal cracks on tool flank, spalling of the cutting edge, and build-up edge from the chip fragments. Depositing the PVD and CVD coat￾ings onto the Al2O3 + SiC(w) oxide tool ceramics results in the significant increase of the tool life and in lowering the roughness parameter value for the machined material, and finally in improvement of its quality, especially at the final machining process stage. Acknowledgements Investigations were partially realized within the frame￾work of the Scientific and Technology Cooperation Joint Project “COAT-CUT” entitled “New generation PVD coat￾ings on tools for dry on high speed cutting processes” be￾tween the Government of the Republic of Poland and the Government of the Republic of Slovenia headed by Prof. L.A. Dobrzanski and Prof. J. Kopa ´ c. Researches were fi- ˇ nanced partially within the framework of the Polish State Committe for Scientific Research Project KBN Nr 3 T08C 04726, headed by Dr. K. Lukaszkowicz and PBZ-100/4/2004 headed by Prof. L.A. Dobrzanski. ´ References [1] L.A. Dobrzanski, Fundamentals of Materials Science and Physical ´ Metallurgy. Engineering Materials with the Fundamentals of Mate￾rials Design, WNT, Warszawa, 2002 (in Polish). [2] L.A. Dobrzanski, E. Hajduczek, J. Marciniak, R. Nowosielski, ´ Physical Metallurgy and Heat Treatment of Tool Materials, WNT, Warszawa, 1990 (in Polish). [3] M. Sokovic, K. Mijanovi ´ c, J. Mater. Process. Technol. 109 (2001) ˇ 181–189. [4] J. Kopac, M. Bahor, M. Sokovi ˇ c, Int. J. Mach. Tools Manuf. 42 ´ (2002) 707–716. [5] J. Mikuła, Structure and properties of Al2O3 based on tool oxide ceramics with wear resistant PVD and CVD coatings, PhD Thesis, Silesian University of Technology, Faculty of Mechanical Engineer￾ing, Gliwice, 2004 (in Polish). [6] S. Novak, M. Sokovic, M. Koma ´ c, B. Pracek, Vacuum 48 (1997) ˇ 107–112. [7] P. Holubar, M. Jilek, M. Sima, Surf. Coat. Technol. 133–134 (2000) 145–151. [8] P. Holubar, M. Jilek, M. Sima, P. Holubar, Surf. Coat. Technol. 120–121 (1999) 184–188. [9] B. Navinsek, P. Panjan, M. Cekada, Surf. Coat. Technol. 154 (2002) 194–203. [10] Grzesik, S. Brol, J. Mater. Process. Technol. 134 (2003) 265–272. [11] W. Grzesik, Int. J. Mach. Tools Manuf. 43 (2003) 145–150. [12] J. Barry, G. Byrne, Wear 247 (2001) 139–151. [13] J.D. Bressan, R. Hesse, E.M. Silva Jr., Wear 250 (2001) 561–568. [14] J. Deng, X. Ai, Tribol. Int. 30 (1997) 807–813. [15] L.A. Dobrzanski, D. Pakuła, E. Hajduczek, J. Mater. Process. Tech- ´ nol. 157–158 (2004) 331–340. [16] D. Pakuła, L.A. Dobrzanski, K. Goł ´ abek, M. Pancielejko, A. Kriz, ˛ J. Mater. Process. Technol. 157–158 (2004) 388–393. [17] A.K. Ghani, I.A. Choudhury, Husni, J. Mater. Process. Technol. 127 (2002) 17–22. [18] L.A. Dobrzanski, K. Gołombek, J. Kopa ´ c, M. Sokovi ˇ c, Mater. Sci. ´ Forum 437–438 (2003) 41–44

M. Sokovic et al. /Journal of Materials Processing Technology 164-165(2005)924-929 [19]LA Dobrzanski, J. Mikula, The Worldwide Congress of Materials [22] L.A. Dobrzanski, J Pakula, J. Kopac, M. Sokovic, Pro- and Manufacturing Engineering and Technology COMMENT, Wisla, ceedings of the 11 Intemational Conference AMME 03 2005(the same issue ). Gliwice-Zakopane, 49-25 20L.A. Dobrzanski, J Mikula, The 13th International Conference on [23L.A. Dobrzansk D. Pakula, A. Kriz, Proceedings of rocessing and Fabrication of Advanced Materials, Singapore, De- he 12th Scientific International Conference AMME 03. Gliwice. mber6-8,2004 Zakopane, 2003, pp 249-252. 21L.A. Dobrzanski, D. Pakula, K. Golombek, J. Mikula, Proceedings 124 L.A. Dobrzanski, J. Mikula, Proceedings of the 1lth International of the 1 lth Scientific International Conference AMME 02. Gliwice Conference on Com Engineering(ICCE-l1), South Ca Zakopane, 2002, pp. 131-134(in Polish) olina,2004,pp.137-138

M. Sokovi´c et al. / Journal of Materials Processing Technology 164–165 (2005) 924–929 929 [19] L.A. Dobrzanski, J. Mikuła, The Worldwide Congress of Materials ´ and Manufacturing Engineering and Technology COMMENT, Wisła, 2005 (the same issue). [20] L.A. Dobrzanski, J. Mikuła, The 13th International Conference on ´ Processing and Fabrication of Advanced Materials, Singapore, De￾cember 6–8, 2004. [21] L.A. Dobrzanski, D. Pakuła, K. Gołombek, J. Mikuła, Proceedings ´ of the 11th Scientific International Conference AMME’02, Gliwice￾Zakopane, 2002, pp. 131–134 (in Polish). [22] L.A. Dobrzanski, J. Mikuła, D. Pakuła, J. Kopa ´ c, M. Sokovi ˇ c, Pro- ´ ceedings of the 11th Scientific International Conference AMME’03, Gliwice-Zakopane, 2003, pp. 249–252. [23] L.A. Dobrzanski, J. Mikuła, D. Pakuła, A. Kriz, Proceedings of ´ the 12th Scientific International Conference AMME’03, Gliwice￾Zakopane, 2003, pp. 249–252. [24] L.A. Dobrzanski, J. Mikuła, Proceedings of the 11th International ´ Conference on Composites/NanoEngineering (ICCE-11), South Car￾olina, 2004, pp. 137–138