形状记忆晶相强韧化Ti基非晶复合材料的组织和力学性能  

Microstructure and Mechanical Properties of Ti-Based Bulk Amorphous Alloys Strengthened and Toughened by Shape-Memory Crystals

作　　者：赵燕春[1,2] 寇生中[1,2] 袁小鹏[1,2] 李春燕[1,2] 蒲永亮[1] 徐娇[1] 

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州730050 [2]兰州理工大学温州泵阀工程研究院,浙江温州325105

出　　处：《稀有金属》2015年第1期29-34,共6页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(50961008);浙江省自然科学基金项目(LQ13E010002);甘肃省高等学校科研项目(2013A-040);兰州市科技发展计划项目(2014-2-9);兰州理工大学红柳青年教师培养计划项目(Q201406)资助

摘　　要：设计了具有形状记忆效应和较强非晶形成能力的(Ti50Ni50-yMy)100-xCux合金,采用悬浮熔炼-水冷铜模吸铸法,通过组元调控制备具有组织连续梯度的形状记忆合金/非晶基复合材料,并研究其组织和力学行为。结果表明:B2-Ti(Ni,Cu)过冷奥氏体相和B19'-Ti(Ni,Cu)热诱发马氏体相析出在铸态非晶基体上,加载断裂应力诱发马氏体相变,马氏体衍射峰比铸态增强且马氏体择优取向。凝固过程的温度梯度决定了复合材料的组织梯度,由表及里,主要为非晶相、马氏体相和奥氏体树枝晶相。加载时形变诱导相变对非晶基体同时增强增韧,复合材料的综合力学性能优异,以连续屈服和强烈的加工硬化为主要特征,(Ti0.5Ni0.48Co0.02)80Cu20断裂强度高达2464 MPa,塑性应变达到13.6%。复合材料断裂表面存在大量密集均匀的脉络纹,析出相周围形成的多重剪切带和玻璃基体上剪切带,扩展方向分别与加载方向呈90°和45°角。（Ti50Ni50-xMx）80Cu20bulk amorphous based composites strengthened and toughened by shape-memory crystals were fabricated by suspend melting under argon atmosphere using a water-cooled Cu mold. And the microstructure and mechanical properties of（ Ti50Ni50- xMx）80Cu20alloy system were studied. The results showed that B2-Ti（ Ni,Cu） supercooled austenite phase and B19＇-Ti（ Ni,Cu） thermally-induced martensite phase precipitated in the amorphous matrix. As loading,stress-induced martensitic transformation occurred before fracture. And the diffraction peak of the martensite with a preferred orientation was strengthened. Microstructure gradient formed as a result of temperature gradient in solidification. From surface to interior,amorphous phase,martensite phase and austenite dendrite phase were observed. The amorphous matrix was strengthened and toughened by deformation induced transformation as loading. The composites exhibited good comprehensive mechanical properties,characterized by good continuous yielding property and strongly work hardening property. And the compressive strength and plastic strain of（ Ti0. 5Ni0. 48Co0. 02）80Cu20were up to 2464 MPa and 13. 6%,respectively. Vein-patterns were uniformly and densely distributed on the fracture surface. The extension directions of the multiple shear bands formed around the precipitates and the main shear bands on the glass matrix,were 90° and 45°at the loading direction,respectively.

关 键 词：非晶复合材料 形变诱导相变 组织 力学性能 

分 类 号：TG139.8[一般工业技术—材料科学与工程]