MSA-25534: No of Pages 9 ARTICLE IN PRESS Materials Science and Engineering A XXx(2009)xXx-XXX Contents lists available at Science Direct Materials Science and engineering A ELSEVIER journalhomepagewww.elsevier.com/locate/msea Fabrication and performance of Al2O3/W, T1)C+ Al2O3/TiC multilayered ceramic cutting tools Deng Jianxin*, Duan Zhenxing, Yun Dongling, Zhang Hui, Ai Xing, Zhao Jun School of Mechanical Engineering, Shandong University, Jinan 250061, Shandong Province, PR China ARTICLE INFO A BSTRACT Al2O3/(W, Ti)C+AlO3/TiC multilayered ceramic cutting tools with different thickness ratios were pro duced by hot pressing. The residual stresses inside the layered materials during fabrication were in revised form 8 September 2009 calculated by means of the finite element method. The mechanical properties at the outer layer of the online xxx yered materials were measured. The cutting performance of the layere compared with an unstressed reference tool. Results showed that multilayered structure in AWT+At layered ceramic materials can induce excess residual stresses during fabrication. These residual stresses Ceramic tools yered materials outer layer of the layered ceramic materials is greatly improved compared with that of the stress-free one. esidual stress These multilayered tools can minimize the flank wear and edge chipping compared with the stress-free tool. The mechanisms responsible were determined to be the formation of compressive residual stress on the outer layer of the layered tools, which led to an increase in resistance to fracture. Thickness ratios were found to have a profound effect on the residual stresses, the fracture toughness, and the cutting performance of the layered tools o 2009 Elsevier B V. All rights reserved. 1. Introduction and offer advantages with respect to friction and wear behaviors Ceramic cutting tools usually perform better in high speed In the past decade, layered ceramics that take advantage of machining and in the machining of high hardness workpiece mate- several strengthening mechanisms, such as crack deflection [7 rials as compared to high-speed steel and carbide tools. However, independence on the initial flaw[8, introduction of weakinterfaces the use of Al2O3 ceramic cutting tools, even fully densified, may 9], containment of martensitic transformation 10, or existence limited by their properties, such as their low strength and frac- of porous layers [11, have been studied extensively. Among them. ture toughness. Since about 1970, Al2 O3 ceramic cutting tools have one of the most common mechanisms is the incorporation of resid- improved remarkably. These improvements are mainly due to[ 1, 2: ual stresses arising from thermal expansion coefficients mismatch, (1)microstructures have been refined by controlling and improving so that the surface layer is under compression. Several mod manufacturing processes: (2)toughening mechanisms have been els and theoretical calculations, and experimental measurement developed, such as whisker toughening and transformation tough- methods have been proposed [8, 12-16 to determine the stress ening, thus improving the fracture toughness of ceramic tools: amount and distribution in laminated structures. These compres and(3)surfaces have been conditioned by the removal of cracks sive stresses can increase the fracture strength, damage resistance, and irregularities. Considerable improvements have been achieved fatigue properties as well as fracture toughness of layered ceram- in tool properties such as flexural strength, fracture toughness, ics (16-28]. The effectiveness of laminated structures in improving hardness, and wear resistance by incorporating one or more other the tribological properties has been reported by tarlazzi et al components into the Al2O3 base material to form ceramic com- [29, 30]. Toschi et al. [31 showed that laminated hybrid struc posite tool materials. The reinforcing component is often in the tures can improve the sliding wear resistance of alumina Portu shape of particles or whiskers. Some of these tool materials, such et al. [32 reported that laminated structure with compressive Al2O3/TiC, Al2O3/TiB2, Al2O3/ZrO2, AlO3/Ti(CN), Al2O3/(WTiC. residual stresses within the surface regions was a suitable and Al2O3/SiCw, have been used in various machining applications to obtain composite materials with superior abrasive wear resis- tance. Deng et al. [33-38 suggested that layered structures in ceramic nozzles can improve their erosion wear resistance in abra- +8653188392047 sive air-jet machining. Nicola [39 produced an alumina/zirconia E-mailaddress:jxdeng@sdu.edu.cn(DJianxin). laminated cutting tool and found that laminated structures are 0921-5093/ S-see front matter o 2009 Elsevier B V. All rights reserved. doi:10.016msea2009.09020 Please cite this article in press as: D Jianxin, et al, Mater Sci Eng. A(2009). doi: 10.1016/j. msea. 2009.09.020Please cite this article in press as: D. Jianxin, et al., Mater. Sci. Eng. A (2009), doi:10.1016/j.msea.2009.09.020 ARTICLE IN PRESS GModel MSA-25534; No. of Pages 9 Materials Science and Engineering A xxx (2009) xxx–xxx Contents lists available at ScienceDirect Materials Science and Engineering A journal homepage: www.elsevier.com/locate/msea Fabrication and performance of Al2O3/(W,Ti)C + Al2O3/TiC multilayered ceramic cutting tools Deng Jianxin∗, Duan Zhenxing, Yun Dongling, Zhang Hui, Ai Xing, Zhao Jun School of Mechanical Engineering, Shandong University, Jinan 250061, Shandong Province, PR China article info Article history: Received 4 August 2009 Received in revised form 8 September 2009 Accepted 8 September 2009 Available online xxx Keywords: Ceramic tools Layered materials Residual stress Al2O3 abstract Al2O3/(W,Ti)C + Al2O3/TiC multilayered ceramic cutting tools with different thickness ratios were pro￾duced by hot pressing. The residual stresses inside the layered materials during fabrication were calculated by means of the finite element method. The mechanical properties at the outer layer of the layered materials were measured. The cutting performance of the layered tools was investigated and compared with an unstressed reference tool. Results showed that multilayered structure in AWT + AT layered ceramic materials can induce excess residual stresses during fabrication. These residual stresses are compressive in the AWT outer layer and tensile in the AT internal layer. The fracture toughness at the outer layer of the layered ceramic materials is greatly improved compared with that of the stress-free one. These multilayered tools can minimize the flank wear and edge chipping compared with the stress-free tool. The mechanisms responsible were determined to be the formation of compressive residual stress on the outer layer of the layered tools, which led to an increase in resistance to fracture. Thickness ratios were found to have a profound effect on the residual stresses, the fracture toughness, and the cutting performance of the layered tools. © 2009 Elsevier B.V. All rights reserved. 1. Introduction Ceramic cutting tools usually perform better in high speed machining and in the machining of high hardness workpiece mate￾rials as compared to high-speed steel and carbide tools. However, the use of Al2O3 ceramic cutting tools, even fully densified, may be limited by their properties, such as their low strength and frac￾ture toughness. Since about 1970, Al2O3 ceramic cutting tools have improved remarkably. These improvements aremainly due to [1,2]: (1) microstructures have been refined by controlling and improving manufacturing processes; (2) toughening mechanisms have been developed, such as whisker toughening and transformation tough￾ening, thus improving the fracture toughness of ceramic tools; and (3) surfaces have been conditioned by the removal of cracks and irregularities. Considerable improvements have been achieved in tool properties such as flexural strength, fracture toughness, hardness, and wear resistance by incorporating one or more other components into the Al2O3 base material to form ceramic com￾posite tool materials. The reinforcing component is often in the shape of particles or whiskers. Some of these tool materials, such as Al2O3/TiC, Al2O3/TiB2, Al2O3/ZrO2, Al2O3/Ti(CN), Al2O3/(WTi)C, and Al2O3/SiCw, have been used in various machining applications ∗ Corresponding author. Tel.: +86 531 88392047. E-mail address: jxdeng@sdu.edu.cn (D. Jianxin). and offer advantages with respect to friction and wear behaviors [3–6]. In the past decade, layered ceramics that take advantage of several strengthening mechanisms, such as crack deflection [7], independence on the initial flaw [8], introduction of weak interfaces [9], containment of martensitic transformation [10], or existence of porous layers [11], have been studied extensively. Among them, one of the most common mechanisms is the incorporation of resid￾ual stresses arising from thermal expansion coefficients mismatch, so that the surface layer is under compression. Several mod￾els and theoretical calculations, and experimental measurement methods have been proposed [8,12–16] to determine the stress amount and distribution in laminated structures. These compres￾sive stresses can increase the fracture strength, damage resistance, fatigue properties, as well as fracture toughness of layered ceram￾ics [16–28]. The effectiveness of laminated structures in improving the tribological properties has been reported by Tarlazzi et al. [29,30]. Toschi et al. [31] showed that laminated hybrid struc￾tures can improve the sliding wear resistance of alumina. Portu et al. [32] reported that laminated structure with compressive residual stresses within the surface regions was a suitable way to obtain composite materials with superior abrasive wear resis￾tance. Deng et al. [33–38] suggested that layered structures in ceramic nozzles can improve their erosion wear resistance in abra￾sive air-jet machining. Nicola [39] produced an alumina/zirconia laminated cutting tool and found that laminated structures are 0921-5093/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.msea.2009.09.020