摘要
对GH3535合金进行不同变形量的拉伸,研究了冷变形对GH3535合金力学性能的影响,用OM、TEM对冷变形后的组织结构进行观察并结合真应力-真应变曲线分析了GH3535合金加工硬化的变形机制。结果表明,GH3535合金具有显著的加工硬化特性,冷变形使其强度和硬度提高,但是塑性降低;随着变形量的增大晶粒沿着变形方向伸长,孪晶变多且更粗大。GH3535合金的加工硬化规律遵循Ludwigson模型,随着冷变形量的增大GH3535合金的加工硬化指数降低,变形机制由单滑移和孪生逐渐变成交滑移和孪生。当变形量小于30%时加工硬化主要是位错的长程应力场和孪晶引起的,当变形量大于30%时主要是位错的短程应力场和形变孪晶引起的。
The effect of extensometer induced cold-tesile deformation on microstructure and mechanical properties of Ni-based high temperature alloy GH3535 were investigated by means of OM and TEM as well as measurement of true stress-true stain curves. It was found that GH3535 alloy shows characteristics of strong work hardening; cold deformation can result in significant increase of its strength and hardness, whereas decrease of its ductility. With the increase of deformation degree grains were elongated along the deformation direction and twins became profusely lager. The work hardening kinetics of GH3535 alloy is constant with Ludwigson model, dislocation slipping and twin are the main deformation mechanism. With the increase of deformation degree the slip behavior of dislocations changes from single slip to cross slip. When the deformation degree below 30% the work hardening is mainly caused by the dislocation long-range stress field and twin, conversely, for the deformation degree above 30% work hardening is mainly caused by the dislocation short-range stress field and deformation twin.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2015年第6期439-444,共6页
Chinese Journal of Materials Research
基金
ANSTO-SINAP联合材料研究项目2014DFG60230
国家自然科学基金51371188和51371189
中国科学院战略性先导科技专项项目XD02004210资助~~
关键词
金属材料
镍基高温合金
冷变形
组织
力学性能
metallic materials,nickel-based superalloy,cold deformation,microstructure,mechanical property
