The effect of Si content on the fatigue crack propagation properties of spray-deposited SiCp/Al-Si composite
The fatigue crack growth experiments of the SiCp(4.5μm)/Al-Si composites with the different Si content(7%, 13% and 20%) were conducted.The results indicate that composite with 20% Si content exhibits highest threshold AKth due to the increase in tensile strength, elastic modulus and yield strength, which resulted in a decrease in the value of crack tip opening distance.At near threshold regimen, the propensity for fatigue crack path deflections, resulted from the crack avoiding the primary Si and eutectic silicon phases, represents an increase with an increase in Si content, and then contributes to a superior resistance to fatigue crack growth for the high Si content composite.However, at Paris and fast fracture regimens, composite exhibits an opposite tendency, i.e.every increase in Si content corresponds to an increase in fatigue crack growth rate.This is attributed to an increased contribution of failure modes at the crack tip through the fracture of the primary Si phase and the formation of micro-cracks originating from the nucleation of many voids at the interface between the Si phase and the matrix at higher AK levels.
composites spray deposition Fatigue crack propagation closure effect Si content
Wei Li Yide Li Cong Li Jian Chen Youping Sun Jianjun He
School of Energy and Power Engineering, Changsha University of Science & Technology, Changsha,Hunan School of Energy and Power Engineering, Changsha University of Science & Technology, Changsha,Hunan Key Laboratory of Reliability Control of Mechanical Manufacturing Technology System, Guangxi Univers
国际会议
长沙
英文
260-269
2016-10-16（万方平台首次上网日期，不代表论文的发表时间）