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为了研究激光线能量密度对TC4合金激光沉积成形组织和质量的影响,进行了成形熔池凝固试验研究。建立了成形过程温度场瞬态有限元数值模型,模拟了TC4合金成形过程的温度场演变过程,并进行了单道单层的成形试验与微观组织的检测。结果表明,良好沉积成形的基本条件是激光功率与扫描速度综合作用的结果,合理的激光线能量密度是良好成形的保证,过小的激光线能量密度不能形成有效熔池,过大又发生过烧现象;随线能量密度增大,由针状晶胞向粒状晶转变,晶粒变得细小均匀,长度变小、宽度增大,当超出合理参数范围,晶胞反而变得粗大;通过试验验证,证明了仿真分析与实际情况基本吻合。
In order to study the effect of laser line energy density on the microstructure and quality of TC4 alloy laser deposition forming, the solidification experiment of forming molten pool was carried out. A transient finite element numerical model of temperature field in forming process was set up to simulate the evolution of temperature field during the forming process of TC4 alloy. The single-layer single-layer forming test and microstructure testing were carried out. The results show that the basic conditions of good deposition and deposition are the result of the combination of laser power and scanning speed. The reasonable laser line energy density is the guarantee of good forming. The too small laser line energy density can not form an effective weld pool. Burning phenomenon; with the line energy density increases, the acicular unit cell to the granular crystal transition, the crystal becomes fine and uniform, the length becomes smaller, the width increases, when beyond the scope of reasonable parameters, the unit cell becomes coarse; through the test Verify that the simulation analysis and the actual situation is basically consistent.