激光立体成形TC4-TA19功能梯度材料的热行为和组织  

Thermal Behavior and Microstructure of TC4-TA19 Functionally Graded Materials by Laser Solid Forming

作　　者：陈昱光 谭华[1,2] 范伟 米泽森[1,2] 林鑫 黄卫东[1,2] CHEN Yuguang;TAN Hua;FAN Wei;MI Zesen;LIN Xin;HUANG Weidong(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China;MIIT Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design,Northwestern Polytechnical University,Xi'an 710072,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]西北工业大学高性能金属增材制造工信部重点实验室,陕西西安710072

出　　处：《铸造技术》2022年第7期497-505,共9页Foundry Technology

基　　金：国家自然基金面上项目(51475380);中央高校基本科研业务费专项资金(3102022gxb001)。

摘　　要：TC4-TA19功能梯度材料可在同一结构不同部位获得不同的性能,具备工程应用潜力和价值。激光立体成形是一种可靠的高性能金属构件制备技术,适用于制造功能梯度材料。本文对激光立体成形TC4-TA19功能梯度材料的成形过程热行为和3种典型成分梯度区的组织形态进行了模拟和实验研究。结果表明,成形温度场和凝固冷却速度受激光功率和层厚的影响显著,受扫描速度影响相对较小,对成分梯度不敏感。成分梯度区组织均由外延生长β柱状晶和晶内交错的α板条组成,其中α板条尺寸主要受合金成分影响,随TC4比例提高不断粗化。成分梯度区中成分界面处的组织具有较高的连续性,成分梯度越小,界面越不明显。成分梯度区具有较高的设计自由度,可通过调控激光功率和层厚优化凝固组织,利于实际生产。TC4-TA19 functionally graded materials can obtain different properties in different parts of the same structure,which has potential and value for engineering application.Laser solid forming is a reliable technique for fabricating high performance metal components,which is very suitable for fabricating functionally graded materials.The thermal behavior of TC4-TA19 functionally graded materials during laser solid forming and the microstructure morphology of three typical component gradient regions have been simulated and experimentally studied.The results show that the forming thermal field and solidification cooling rate are significantly affected by laser power and layer thickness,but less affected by scanning speed,and are not sensitive to component gradient.The microstructure in the composition gradient region is composed ofβcolumnar crystals grown by epitaxial growth andαlath interlaced within the crystals.Theαlath size is mainly affected by the composition of the alloy,and coarser with the increase of TC4 ratio.In the composition gradient region,the microstructure at the interface exhibit a high continuity,and the smaller the composition gradient,the less obvious the interface.The composition gradient zone has high design freedom and can optimize the solidification structure by adjusting laser power and layer thickness,which is beneficial to practical production.

关 键 词：功能梯度材料 激光立体成形 温度场 冷却速率 微观组织 

分 类 号：TG113.1[金属学及工艺—物理冶金]