Effect of SiC particles on fatigue crack growth behavior of spray-formed SiC particulate-reinforced Al-Si alloy composites
Fatigue crack growth (FCG) and closure mechanisms in spray-formed Al-7Si alloy matrix composites reinforced with two different sizes of SiC particles has been studied.The experimental dates demonstrate that the composite containing 4.5μm SiC particles exhibits lower FCG rate and higher threshold stress intensity factor range ΔKth (3.878 ΜΡa ?(√) m ) than the 20μm SiC particles composite(3.630 ΜΡa ?(√) m ) and the unreinforced alloy (3.605 ΜΡa ?(√) m ).The SEM crack path observations show that the extent of micoracking inside in the 4.5μm SiC particles induces higher level of fatigue crack closure,which effectively reduces the crack growth driving force to slow down fatigue crack growth.Crack deflection caused by the SiC particles attributes the lower FCG rate in the 20μm SiC composite to the high levels of roughness-induced crack closure at the low ΔK,then the propensity for the fracture of large SiC particles increased with increasing ΔK resulted in a higher FCG rate in the fast fracture state.
Fatigue crack growth spray-formed SiC particulate-reinforced Al-Si alloy composites closure mechanism size
Li Wei Chen Jian Qiu Wei Ren Yanjie
School of Energy and Power Engineering,Changsha University of Science and Technology,410004,China
国际会议
北京
英文
1-10
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）