激光沉积车用WC-0.25Ti粉末增强7056铝合金板成形性能分析  

Laser deposition of WC-0.25Ti powder-enhanced 7056 aluminum alloy plate forming performance analysis

作　　者：甘守武[1] 陈志军[1] 李蕊[1] GAN Shou-wu;CHEN Zhi-jun;LI Rui(School of intelligent manufacturing and automobile,Chongqing vocational college of electronic engineering,Chongqing 401331,China)

机构地区：[1]重庆电子工程职业学院智能制造与汽车学院,重庆401331

出　　处：《粉末冶金工业》2020年第5期73-77,共5页Powder Metallurgy Industry

基　　金：重庆市教委项目:“重庆市高等学校优秀人才支持计划项目”(800213)。

摘　　要：选择激光沉积方法在各项工艺参数下的叠层沉积件,表征其显微组织结构与物相成分。研究结果表明:当气流流量提高后,可以得到更多的下沉WC颗粒,WC形成了均匀分布状态。随着气流量的增加,激光功率明显减小。30 L/min气流成形试件从第一层开始逐渐减小激光功率,越有利于积聚热量的散失,此时WC颗粒占总面积的比例为23.5%。宽度从第四层开始明显增加,逐渐形成了蘑菇状的叠层沉积件。在沉积层内存在Al、WC、Ti、TiC、Si、Al3Ti等多种组织相,并没有生成Al4C3脆性相。从下往上厚度依次增加,此时柱状枝晶逐渐转变为树枝晶。对于存在WC与Ti的部位,柱状晶生长过程将被显著抑制,晶粒尺寸减小。当沉积层高度增加后,枝晶的尺寸也不断变大,介于100~180μm。The laser deposition method was used to characterize the microstructure and phase composition of the laminated parts under various technological parameters.The research results show that when the air flow rate increases,and the more sinking WC particles can be obtained,the WC forms a uniform distribution state.With the increasing of gas flow,the laser power decreases obviously.The specimen formed by the 30 L/min airflow gradually reduces the laser power from the first layer,which is more conducive to heat accumulation loss.At this time,WC particles account for 23.5%of the total area.The width increased significantly from the fourth layer,gradually forming a mushroom-like laminate.The Al,WC,Ti,TiC,Si,Al3 Ti and other tissue facies exist in the sedimentary layer,but Al4 C3 brittle phase is not generated.The thickness increases from bottom to top and then the columnar dendrites become dendrites gradually.In the presence of WC and Ti,the columnar crystal growth process will be significantly inhibited and the grain size will decrease.As the height of the sediments increased,the dendrites grew in size,ranging from 100-180μm.

关 键 词：激光沉积 WC-0.25Ti粉末 物相成分 微观组织 

分 类 号：TG665[金属学及工艺—金属切削加工及机床] TB331[一般工业技术—材料科学与工程]