tailieunhanh - Báo cáo hóa học: " Atomistic aspects of ductile responses of cubic silicon carbide during nanometric cutting"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Atomistic aspects of ductile responses of cubic silicon carbide during nanometric cutting | Goel et al. Nanoscale Research Letters 2011 6 589 http content 6 1 589 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Atomistic aspects of ductile responses of cubic silicon carbide during nanometric cutting Saurav Goel Xichun Luo Robert L Reuben and Waleed Bin Rashid Abstract Cubic silicon carbide SiC is an extremely hard and brittle material having unique blend of material properties which makes it suitable candidate for microelectromechanical systems and nanoelectromechanical systems applications. Although SiC can be machined in ductile regime at nanoscale through single-point diamond turning process the root cause of the ductile response of SiC has not been understood yet which impedes significant exploitation of this ceramic material. In this paper molecular dynamics simulation has been carried out to investigate the atomistic aspects of ductile response of SiC during nanometric cutting process. Simulation results show that cubic SiC undergoes sp3-sp2 order-disorder transition resulting in the formation of SiC-graphene-like substance with a growth rate dependent on the cutting conditions. The disorder transition of SiC causes the ductile response during its nanometric cutting operations. It was further found out that the continuous abrasive action between the diamond tool and SiC causes simultaneous sp3-sp2 order-disorder transition of diamond tool which results in graphitization of diamond and consequent tool wear. Keywords ductile regime nanometric cutting silicon carbide diamond tool tool wear Introduction Silicon carbide SiC is a promising ceramic material suited for advanced neural interfaces packaging for long-term implantation microfabricated neural probe as well as for semiconductor devices used in severe environments such as in military aircraft combat vehicles power generation and petrochemical industries 1 . SiC is a very hard substance 9 to on Mohs scale having comparable hardness to the .