摘要
借助激光同轴送粉增材制造技术制备TiAl合金,深入探究了不同激光功率下合金冶金缺陷的演变规律,分析了合金的相组成、显微组织及力学性能。结果表明,随着激光功率增加,TiAl合金单熔道的熔宽和熔深逐渐增大,球化现象逐渐减弱。合金具有较高的致密度,孔隙率均小于0.05%,并且随着激光功率增加,孔隙率略有降低。激光功率为1200 W时,试样与基材界面附近出现裂纹,激光功率增加至1400、1600 W时,裂纹消失。TiAl合金主要由γ-TiAl相及少量的α_(2)-Ti_(3)Al相组成,其显微组织特征是γ/α_(2)片层晶团边界处分布着少量块状γ晶粒。随着激光功率的增大,TiAl合金的片层晶团尺寸呈现逐渐增大的趋势。激光功率为1400 W时,TiAl合金的抗拉强度为476 MPa,其拉伸断口形貌呈现脆性断裂特征。
The TiAl alloys were prepared by laser coaxial powder feeding additive manufacturing technology,and the evolution of metallurgical defects in the alloy under different laser powers was thoroughly investigated,and the phase composition,microstructure,and mechanical properties of the alloy were analyzed.The results indicate that as the laser power increases,the melt width and depth of the single melt track in the TiAl alloy gradually grow,and the spheroidization phenomenon diminishes.The alloys demonstrate a high density,with porosity below 0.05%,and the porosity slightly decreases as the laser power increases. When the laser power is 1 200 W, cracks appearnear the interface between the formed part and the base material. When the laser power is increased to 1 400 W and1 600 W, the cracks disappear. The TiAl alloys are mainly composed of the γ phase and a small amount of the α_(2)phase. Their microscopic structure feature is that a small number of blocky γ grains are distributed at the boundariesof the γ/α_(2) lamellar colonies. With the increase of the laser power, the size of the lamellar colonies of the TiAl alloysshows a gradually increasing trend. When the laser power is 1 400 W, the tensile strength of the TiAl alloy is476 MPa, and the tensile fracture morphology exhibits the characteristics of brittle fracture.
作者
王虎
赵琳
香勇
彭云
田志凌
WANG Hu;ZHAO Lin;XIANG Yong;PENG Yun;TIAN Zhiling(College of Materials Engineering,North China Institute of Aerospace Engineering,Langfang 065000,China;Central Iron and Steel Research Institute,Beijing 100081,China;Tsing Bosch(Zhuhai)Technology Co.,Ltd.,Zhuhai 519085,China)
出处
《粉末冶金工业》
北大核心
2025年第4期157-163,共7页
Powder Metallurgy Industry
基金
中央引导地方科技发展资金资助项目(246Z1816G)
北华航天工业学院科研基金资助项目(CXPT202402)。
关键词
激光同轴送粉增材制造
钛铝合金
激光功率
冶金缺陷
显微组织
力学性能
laser coaxial powder feeding additive manufacturing
TiAl alloy
laser power
metallurgical defect
microstructure
mechanical property
作者简介
王虎(1986-),男,博士,副教授,主要研究方向为增材制造、表面工程;通信作者:香勇(1977-),男,博士,正高级工程师,主要研究方向为无损检测、增材制造。
