摘要
通过研究选区激光熔化Ti-6Al-4V合金件不同热处理制度下组织结构转变规律,揭示其热处理工艺—组织结构—力学性能内在联系。结果表明:在600~700℃范围内,合金中α^′马氏体未完全分解,形成α′和α+β混合组织,合金的强度较高,延伸率偏低;温度升高至800~900℃时,α′马氏体完全转变为稳定的α+β层片组织结构;热等静压后,合金亚稳α′马氏体完全转变为α+β层,局部区域出现粗化;随着热处理温度的升高,相对于沉积态,合金的屈服强度和抗拉强度逐渐降低,断后延伸率逐渐增加;结合微观组织晶粒的长大行为,沉积钛合金退火温度、时间选择800℃、2 h为宜。
The microstructure of Ti-6 Al-4 V alloy fabricated by selective laser melting was studied at different heat treatment conditions to reveal the internal relation during the heat treatment process,microstructure and mechanical properties.The results show that at 600~700℃α′martensite in the alloy is not completely decomposed to form a mixed microstructure ofα′andα+β,resulting in a high strength and low elongation for the alloy.When the temperature increases to 800~900℃,α′martensite in the alloy can be fully transformed into steady lamellarα+β.After hot isostatic pressure,the metastableα′martensite is completely converted to lamellarα+βand some local areas in the alloy are coarsened.With increase of the heat treatment temperature,the yield strength and tensile strength of the alloy are gradually decreased coupled with gradual increase of the specific elongation,compared with the deposition state.The optimum annealing temperature and holding time of the as-fabricated samples are determined at 800℃for 2 h in combination with the growth behavior of grains.
作者
马超
王磊
付小强
Ma Chao;Wang Lei;Fu Xiaoqiang(Shanghai Aircraft Manufacturing Co.,Ltd.,Shanghai 200436,China)
出处
《钢铁钒钛》
CAS
北大核心
2019年第4期51-58,共8页
Iron Steel Vanadium Titanium
基金
上海飞机制造有限公司宽体客机工艺研发与验证项目
上海市国际科技合作基金项目(15520701400)
