摘要
以Ti、Al、V混合元素粉末为原料激光沉积Ti-6Al-4V,并对沉积态试样的组织演化及力学性能进行研究。结果表明,与采用预合金Ti-6Al-4V粉末为原料所获得的沉积试样的凝固组织特征有所不同,采用混合元素粉末为原料获得的沉积试样的凝固组织随激光功率的提高逐渐由等轴晶转化为柱状晶,熔池内合金化过程所产生的混合热的扰动作用是导致低功率条件下等轴晶形成的原因。原始β晶粒内的微观组织由大量的魏氏α板条和一定体积分数的板条间β相组成。这与采用预合金粉末基本相同。混合元素法激光立体成形Ti-6Al-4V的氧含量仅约0.1wt.%,沉积态Ti-6Al-4V的室温拉伸性能超过锻件标准要求。
The microstructure and mechanical properties of laser solid formed Ti-6Al-4V from the blend of Ti, Al, and V powders were investigated. It is found that the macrostructure changes from equiaxed to columnar grains with the increase of the laser power, which is very different from that of the samples using pre-alloyed powders as cladding materials. The disturbance effect of the mixing enthalpy during laser deposition is considered responsible for the formation of equiaxed grains at low laser powers. The microstructure within prior-fl grains mainly consists of Widmanst^tten a laths separated by fl-Ti, which is basically identical to those from pre-alloyed powders. Oxygen content of as-deposited samples was measured and the tensile testing was carded out. The results show that the oxygen content of as-deposited Ti-6Al-4V from blended elemental powders is only about 0. 1wt.% and the mechanical properties are comparable to or even better than that of conventionally wrought material.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2009年第4期574-578,共5页
Rare Metal Materials and Engineering
基金
National Natural Science Foundation of China(No.50871089)
Talent Cultivating Program of Northwestern Polytechnical University(GrantNo.05XE0131)
National Basic Research Program("973"Program)of China(No.2007CB613805)
Program for New Century Excellent Talentsin University of China(Grant No.NCET-06-0879).
关键词
混合元素粉末
激光立体成形
TI-6AL-4V
组织
性能
blended elemental powders
laser solid forming
Ti-6Al-4V
microstructure
mechanical properties
