研究了Cu Al Be B形状记忆合金的成分、微观组织和相结构与阻尼和力学性能的关系 ,通过扫描电镜原位观察合金在单向拉伸应力作用下裂纹萌生和扩展的特征。结果表明 :应力诱发马氏体变体的转变使Cu Al Be B合金具有较高的阻尼性能 ;弹性...研究了Cu Al Be B形状记忆合金的成分、微观组织和相结构与阻尼和力学性能的关系 ,通过扫描电镜原位观察合金在单向拉伸应力作用下裂纹萌生和扩展的特征。结果表明 :应力诱发马氏体变体的转变使Cu Al Be B合金具有较高的阻尼性能 ;弹性各向异性和相变应变差引发晶界应力集中 ,导致合金在拉伸条件下发生晶间断裂 ;18R与 2H马氏体混合程度大时 ,会增加相变应变差引起的晶界应力集中和可能萌生的晶界裂纹源 ,大大减小合金的塑性和强度。展开更多
This paper investigated high-damping Cu-Al-Be-B cast alloys using metallographic analysis, X-ray diffraction (XRD) and electrical resistance measurements for transformation temperatures. The results showed that beryll...This paper investigated high-damping Cu-Al-Be-B cast alloys using metallographic analysis, X-ray diffraction (XRD) and electrical resistance measurements for transformation temperatures. The results showed that beryllium can stabilize β phase, resulting in a thermo-elastic martensite microstructure leading to high-damping capacity in cast Cu-Al-Be-B alloys. Trace additions of boron to Cu-Al-Be alloys can significantly refine the grains, providing high strength and ductility to the alloys. A factorial design of experiment method was used to optimize the composition and properties of cast Cu-Al-Be-B alloys. The optimal microstructure for thermo-elastic martensite can be obtained by adjusting the amounts of aluminum and beryllium to eutectoid or pseudo-eutectoid compositions. An optimized cast Cu-Al-Be-B alloy was developed to provide excellent mechanical properties, tensile strength σ_b=767MPa, elongation δ=7.62%, and damping capacity S. D. C=18.70%.展开更多
采用扫描电镜、X射线衍射分析等手段 ,研究了正火处理对Cu Al Be B合金组织、相结构及阻尼和力学性能的影响 ,并原位观察拉伸应力作用下裂纹的萌生和扩展过程。研究结果表明 ,Cu Al Be B合金具有较高的阻尼性能 (S D C =17%～ 19% ) ,...采用扫描电镜、X射线衍射分析等手段 ,研究了正火处理对Cu Al Be B合金组织、相结构及阻尼和力学性能的影响 ,并原位观察拉伸应力作用下裂纹的萌生和扩展过程。研究结果表明 ,Cu Al Be B合金具有较高的阻尼性能 (S D C =17%～ 19% ) ,正火处理可抑制α相的析出 ,并减少γ1′的混杂程度 ,从而进一步提高阻尼能力。各向弹性异性和相变应变差引起的晶界集中应力 ,导致Cu A1 Be B合金在拉伸条件下发生晶间断裂。正火处理不但纯净晶界 ,形成马氏体共格晶界 ,而且减小晶内γ1′马氏体与 β1′马氏体的混合程度 ,有利于减少晶界应力集中和可能萌生的晶界裂纹源 ,从而有效改善合金的塑性和强度。展开更多
文摘研究了Cu Al Be B形状记忆合金的成分、微观组织和相结构与阻尼和力学性能的关系 ,通过扫描电镜原位观察合金在单向拉伸应力作用下裂纹萌生和扩展的特征。结果表明 :应力诱发马氏体变体的转变使Cu Al Be B合金具有较高的阻尼性能 ;弹性各向异性和相变应变差引发晶界应力集中 ,导致合金在拉伸条件下发生晶间断裂 ;18R与 2H马氏体混合程度大时 ,会增加相变应变差引起的晶界应力集中和可能萌生的晶界裂纹源 ,大大减小合金的塑性和强度。
文摘This paper investigated high-damping Cu-Al-Be-B cast alloys using metallographic analysis, X-ray diffraction (XRD) and electrical resistance measurements for transformation temperatures. The results showed that beryllium can stabilize β phase, resulting in a thermo-elastic martensite microstructure leading to high-damping capacity in cast Cu-Al-Be-B alloys. Trace additions of boron to Cu-Al-Be alloys can significantly refine the grains, providing high strength and ductility to the alloys. A factorial design of experiment method was used to optimize the composition and properties of cast Cu-Al-Be-B alloys. The optimal microstructure for thermo-elastic martensite can be obtained by adjusting the amounts of aluminum and beryllium to eutectoid or pseudo-eutectoid compositions. An optimized cast Cu-Al-Be-B alloy was developed to provide excellent mechanical properties, tensile strength σ_b=767MPa, elongation δ=7.62%, and damping capacity S. D. C=18.70%.
文摘采用扫描电镜、X射线衍射分析等手段 ,研究了正火处理对Cu Al Be B合金组织、相结构及阻尼和力学性能的影响 ,并原位观察拉伸应力作用下裂纹的萌生和扩展过程。研究结果表明 ,Cu Al Be B合金具有较高的阻尼性能 (S D C =17%～ 19% ) ,正火处理可抑制α相的析出 ,并减少γ1′的混杂程度 ,从而进一步提高阻尼能力。各向弹性异性和相变应变差引起的晶界集中应力 ,导致Cu A1 Be B合金在拉伸条件下发生晶间断裂。正火处理不但纯净晶界 ,形成马氏体共格晶界 ,而且减小晶内γ1′马氏体与 β1′马氏体的混合程度 ,有利于减少晶界应力集中和可能萌生的晶界裂纹源 ,从而有效改善合金的塑性和强度。
