Materials Science and Engineering A 507(2009)6-12 Contents lists available at Science Direct Materials Science and Engineering A LSEVIER journalhomepagewww.elsevier.com/locate/msea Influence of the strain rate on the mechanical behavior of the 3D needle-punched C/Sic composite Yulong Li*, Tao Suo, Mingshuang Liu School of Aeronautics, Northwestern Polytechnical University, P.O. Box 118, XI'an 710072, People's Republic of china ARTICLE INFO ABSTRACT Compressive mechanical behavior of a 3D needle-punched C/Sic composite at room temp investigated at strain rate ranging from 10-4 to 6.5 x 1031/s using the electronic universal test 15 November 2008 nd the split Hopkinson pressure bar. The experimental results show the strain rate has slig Accepted 7 January 2009 on the mechanical property of the material. The dynamic compression strength obeys the bution with the Weibull parameter m calculated as 8 19. Scanning electron microscope(SI of the fracture surface of specimens tested at various strain rates indicate that the failure pat D needle-punched C/SiC composites material also varies with the strain rate Mechanical properties o2009 Elsevier B V. All rights reserved. Dynamic compression strength Damage angle 1. Introduction matrix. Recently, Fan et al.[14 and Xu et al. [11 analyzed its fri tion performance and suggested that the grain-abrasion was the Carbon fiber-reinforced Sic-matrix composites (C/Sic) have main wear mechanism of the material. The mechanical behavior of such advantages as low density, high ratios of stiffness/ weight 3D needle-punched C/Sic composite under quasi-static loading at temperature conditions, all of which have enabled their extensive that the bending strength vertical to layers was weaker than the pplication in many engineering structures, especially in aeronau- strength parallel to layers, while the compression strength vertical tic and aerospace fields [ 1. The C/Sic composites developed can to layers almost equaled that parallel to the layers. However, to the be grouped into 2D composites and 3D ones. The interface shear best of our knowledge, the dynamic compressive behavior of 3D strength of 2D-C/Sic composites was found by many researchers to needle-punched C/Sic composite has not yet been reported be relatively weak [2-6. To overcome this disadvantage 3D C/Sic In this paper, the uniaxial compressive behavior of a 3D needle- composites were developed [7. Among them, 3D woven C/SiC com- punched C/Sic composite was investigated under both quasi-static posites and 3D needle-punched C/Sic composites were the most and dynamic loadings at room temperature. The failure pattern was widely investigated ones. While the experimental results of the 3D observed via a scanning electron microscope(SEM). woven C/SiC composites exhibit remarkable anisotropy [8-10, the research results of the 3D needle-punched c/SiC composite demon- 2. Experimental procedure strate that its interface shear strength as well as the mechanical erosion resistance could benefit from the special microstructure of 2.1. Material preparation the material [11, 12] Considerable interest has been focused on 3D needle-punched The 3D needle-punched C/Sic composite tested in this study C/SiC composite in recent years. Microstructure and flexural prop- was offered by the State Key Laboratory of Solidification Process erties of a 3D C/SiC composite was examined by Xiao et al.[13]. ing in Northwestern Polytechnical University, Peoples Republic from which the composite was found to be damaged layer by of China. The carbon fiber utilized was T300 carbon fiber from layer with good pseudo-plasticity and that pyrolytic carbon coat- the Nippon Toray Corporation. The quasi 3D reinforced preform ing could moderate the interface strength between C fibers and si was firstly prepared by three-dimensional braided Then isothermal/ isobaric CVI(ICVI)was employed to depo the surface of carbon fiber Corresponding author. TeL: +86 29 8849 4859: fax: +86 29 8849 4859. layer with butane at 850C prior to densification. Finally, methyl mail address: liyulong@nwpueduce (Y Li). trichlorosilane was used for deposition of the Sic matrix to get the 5093/s-see front matter o 2009 Elsevier B V. All rights reserved. 01016 j.msea200901024Materials Science and Engineering A 507 (2009) 6–12 Contents lists available at ScienceDirect Materials Science and Engineering A journal homepage: www.elsevier.com/locate/msea Influence of the strain rate on the mechanical behavior of the 3D needle-punched C/SiC composite Yulong Li ∗, Tao Suo, Mingshuang Liu School of Aeronautics, Northwestern Polytechnical University, P.O. Box 118, Xi’an 710072, People’s Republic of China article info Article history: Received 4 May 2008 Received in revised form 15 November 2008 Accepted 7 January 2009 Keywords: 3D needle-punched C/SiC composites Mechanical properties High strain rate Dynamic compression strength Damage angle abstract Compressive mechanical behavior of a 3D needle-punched C/SiC composite at room temperature was investigated at strain rate ranging from 10−4 to 6.5 × 103 1/s using the electronic universal testing machine and the split Hopkinson pressure bar. The experimental results show the strain rate has slight influence on the mechanical property of the material. The dynamic compression strength obeys the Weibull dis￾tribution with the Weibull parameter m calculated as 8.19. Scanning electron microscope (SEM) images of the fracture surface of specimens tested at various strain rates indicate that the failure pattern of the material also varies with the strain rate. © 2009 Elsevier B.V. All rights reserved. 1. Introduction Carbon fiber-reinforced SiC-matrix composites (C/SiC) have such advantages as low density, high ratios of stiffness/weight and strength/weight, and failure stress that sustains under high temperature conditions, all of which have enabled their extensive application in many engineering structures, especially in aeronau￾tic and aerospace fields [1]. The C/SiC composites developed can be grouped into 2D composites and 3D ones. The interface shear strength of 2D-C/SiC composites was found by many researchers to be relatively weak [2–6]. To overcome this disadvantage, 3D C/SiC composites were developed [7]. Among them, 3D woven C/SiC com￾posites and 3D needle-punched C/SiC composites were the most widely investigated ones. While the experimental results of the 3D woven C/SiC composites exhibit remarkable anisotropy [8–10], the research results of the 3D needle-punched C/SiC composite demon￾strate that its interface shear strength as well as the mechanical erosion resistance could benefit from the special microstructure of the material [11,12]. Considerable interest has been focused on 3D needle-punched C/SiC composite in recent years. Microstructure and flexural prop￾erties of a 3D C/SiC composite was examined by Xiao et al. [13], from which the composite was found to be damaged layer by layer with good pseudo-plasticity and that pyrolytic carbon coat￾ing could moderate the interface strength between C fibers and SiC ∗ Corresponding author. Tel.: +86 29 8849 4859; fax: +86 29 8849 4859. E-mail address: liyulong@nwpu.edu.cn (Y. Li). matrix. Recently, Fan et al. [14] and Xu et al. [11] analyzed its fric￾tion performance and suggested that the grain-abrasion was the main wear mechanism of the material. The mechanical behavior of 3D needle-punched C/SiC composite under quasi-static loading at room temperature was also investigated by Wan [12], who reported that the bending strength vertical to layers was weaker than the strength parallel to layers, while the compression strength vertical to layers almost equaled that parallel to the layers. However, to the best of our knowledge, the dynamic compressive behavior of 3D needle-punched C/SiC composite has not yet been reported. In this paper, the uniaxial compressive behavior of a 3D needle￾punched C/SiC composite was investigated under both quasi-static and dynamic loadings at room temperature. The failure pattern was observed via a scanning electron microscope (SEM). 2. Experimental procedure 2.1. Material preparation The 3D needle-punched C/SiC composite tested in this study was offered by the State Key Laboratory of Solidification Process￾ing in Northwestern Polytechnical University, People’s Republic of China. The carbon fiber utilized was T300 carbon fiber from the Nippon Toray Corporation. The quasi 3D reinforced preform was firstly prepared by three-dimensional braided method. Then isothermal/isobaric CVI (ICVI) was employed to deposit a thin pyrol￾ysis carbon layer on the surface of carbon fiber as the interfacial layer with butane at 850 ◦C prior to densification. Finally, methyl￾trichlorosilane was used for deposition of the SiC matrix to get the 0921-5093/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.msea.2009.01.024