热氢处理对MIMTi-6Al-4V组织及性能的影响  

Influences of Thermo-hydrogenation Treatment on the Microstructure and Properties of MIM Ti-6Al-4V Alloy

作　　者：雷豹[1] 肖平安[1] 周威[1] 张小虎[1] 范安平[1] 

机构地区：[1]湖南大学,湖南长沙410082

出　　处：《稀有金属材料与工程》2013年第5期1057-1061,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51074070;50674044)

摘　　要：系统研究了热氢处理过程中MIMTi-6Al-4V相组成和显微组织的演变规律,尤其是置氢量变化带来的影响,以实现通过热氢处理改善合金力学性能的目的。结果表明,在650℃置氢时,随着置氢量的增加,首先合金中的β相增多,然后开始析出δ相氢化物,并形成越来越多的细小针状组织。在850℃进行固溶和620℃进行等温时效使得合金中的溶氢分布更均匀,δ相的析出更充分,针状组织更加丰富。在720℃进行真空除氢处理后,合金的显微组织保持了细小针状组织的特征,并且置氢量越大时除氢后显微组织的细化效果越显著。置氢量为0.51%(质量分数,下同)时MIMTi-6Al-4V经热氢处理后极限抗拉强度、屈服强度和伸长率分别提高11%、13%和19%。Both the phase and microstructure evolution of MIM Ti-6Al-4V alloy in the thermo-hydrogenation treatment process were investigated, especially the effect of hydrogen content, to improve mechanical properties. The results show that β-Ti becomes more and more initially and then δ titanium hydride is precipitated as hydrogen content in the alloy increases during the hydrogenation process at 650 °C, so that the bulky sheets in the microstructure of as-MIMed alloy are gradually broken into tiny needles. Solution treatment at 850 °C and isothermal aging at 620 °C make the dissolved hydrogen in the alloy distribute more uniformly and let more needle-like δ precipitate. The alloy remains a refined needle-like microstructure after vacuum dehydrogenation at 720 °C, and the higher the dissolved hydrogen content in the hydrogenised alloy, the more the refined needle-like microstructure after dehydrogenation. For the alloy with 0.51wt% H after hydrogenation, its ultimate tensile strength, yield strength and elongation after dehydrogenation are increased by 11%, 13% and 19%, respectively, in comparison with those of MIM Ti-6Al-4V.

关 键 词：TI-6AL-4V 热氢处理 显微组织 相组成 力学性能 

分 类 号：TG156.8[金属学及工艺—热处理]