摘要
A rectangular plate of Ti-6.5A1-3.5Mo-I.5Zr-0.3Si titanium alloy was fabricated by laser melting deposition （LMD） technology. Macrostructure and microstructure were characterized by optical microscope （OM） and scanning electron microscope （SEM）. Room temperature tensile properties were evaluated. Results indicate that the macro-morphology is dominated by large columnar grains traversing multiple deposited layers. Two kinds of bands, named the wide bands and the narrow bands, are observed. The wide band consists of crab-like a lath and Widmanstatten a colony. The narrow band consists of a lath and transformed ft. The formation mechanism of the two bands was explored. The influence of heat effect caused by subsequent deposition layers on microstructural evolution during deposition process was discussed. The room temperature tensile test demonstrates that the strength of laser deposited Ti-6.5A1-3.5Mo-I.5Zr-0.3Si is comparable to that of wrought bars.
利用激光熔化沉积技术制备Ti-6.5Al-3.5Mo-1.5Zr-0.3Si钛合金板材,并采用金相和扫描电镜对合金的宏观组织和微观组织进行表征,对室温拉伸性能进行研究。结果显示:宏观形貌由贯穿多个沉积层的大柱状晶组成;观察到宽条带和窄条带2种条带,宽条带由α板条和魏氏集束构成,窄条带由α板条和β转变组织构成,对条带的形成机理进行探讨。此外,还讨论由后续沉积层的沉积导致的热效应对组织演变的影响。室温拉伸测试显示,激光熔化沉积制备的Ti-6.5Al-3.5Mo-1.5Zr-0.3Si钛合金的强度达到锻件强度水平。
基金
Project(2011CB606305) supported by the National Basic Research Program of China
