拉伸速率对Ni_(40)Ti_(50)Fe_(10)合金环境氢脆的影响  

Effect of Strain Rate on Environmental Embrittlement of Ni_(40)Ti_(50)Fe_(10) Alloy

作　　者：谭晓华[1] 程晓英[1] 徐晖[1] 

机构地区：[1]上海大学材料研究所,上海200072

出　　处：《材料科学与工艺》2006年第5期532-534,共3页Materials Science and Technology

基　　金：上海市教委资助项目(02AK28)

摘　　要：研究了不同应变速率对N i40Ti50Fe10合金环境氢脆的影响,并用扫描电子显微镜观察了拉伸断口的形貌.研究结果表明:N i40Ti50Fe10合金在真空中的拉伸行为与应变速率无关,断口形貌主要是韧窝塑性断口.N i40Ti50Fe10合金在空气中的塑性随着应变速率的降低而减小,断口形貌也从韧窝塑性断口转变为韧窝塑性断口和解理脆性断口的混合断口.N i40Ti50Fe10合金在氢气中低应变速率拉伸时表现出明显的脆性,断口形貌主要为解理脆性断口.在高应变速率下(2×10-1s-1),N i40Ti50Fe10合金在真空、空气和氢气中的塑性相近,说明在该应变速率下可以有效地抑制环境氢脆.N i40Ti50Fe10合金的屈服强度不受应变速率和环境的影响.The mechanical properties of Ni40Ti50Fe10 alloy were investigated by tensile tests at different strain rates in various environments. The fracture surfaces of Ni40Ti50Fe10 alloy were examined by scanning electron microscopy （SEM）. The results indicated that the strain rate did not affect the tensile behavior of Ni40Ti50Fe10 alloy tested in vacuum. The fracture surface is dimple fracture for Ni40Ti50Fe10 alloy tested in vacuum. The tensile ductility of specimen decreases with the decreasing strain rate in air. The fracture surface tested in air shows a mixed mode of dimple fracture and cleavage patterns. Ni40Ti50Fe10 alloy exhibits serious embrittlement when tested at low strain rate in hydrogen. The fracture surface is mainly cleavage patterns for specimen tested in hydrogen. The values of elongation for Ni40Ti50Fe10 alloy tested in different environment at high strain rate （2 × 10^-1s^-1 ） are almost the same, indicating that the strain rate is high enough to suppress the environmental embrittlement effectively. The yield stress of Ni40Ti50Fe10 alloy is independent on the environment and strain rate.

关 键 词：Ni40Ti50Fe10合金 环境氢脆 应变速率 

分 类 号：TG111.91[金属学及工艺—物理冶金]