激光选择熔化成形工艺参数对多孔钛结构的影响及成孔机理  

Effect of Process Parameters on Porous Titanium Structure and Mechanism of Porous Formation in Selective Laser Melting

作　　者：张超[1] 陈长军[2] 王晓南[3] 张敏[2] 敬和民[1] 

机构地区：[1]安徽工业大学材料科学与工程学院,安徽马鞍山243002 [2]苏州大学机电学院激光加工中心,江苏苏州215021 [3]苏州大学沙钢钢铁学院,江苏苏州215021

出　　处：《中国激光》2013年第B12期60-65,共6页Chinese Journal of Lasers

基　　金：苏州市科技基础研究计划项目（SYG201231）、国家自然科学基金（51305285）

摘　　要：为丰富生物医用多孔钛的制备方法，采用激光选择熔化成形技术制备了多孔钛，着重研究了光斑直径／扫描间距（D／d）值及粉末组成对多孔钛结构的影响、主孔及微孔的形成机理。结果表明：实验粉末为95％Ti＋5％TiH2（95％，5％为质量分数）、D／d值为1时，多孔钛孔隙由主孔和微孔构成，微孔将部分主孔连通，形成三维连通结构；激光束选择性地作用于预置粉末，预留的未被辐照区域形成主孔，是否存在主孔由D／d值决定，D／d=2时不产生主孔，D／d=1时产生主孔；激光作用下TiH2分解产生H2，在极快速凝固条件及“活塞效应”的协同作用下，部分Hz来不及从钛熔池中逸出而形成微孔，微孔对样品的孔隙率影响不明显，但微孔的存在明显提高了样品的开孔率。In order to enrich the preparation methods of biomedical porous Ti, a technology of selective laser melting is used to prepare porous Ti. The effect of spot diameter/scan space （D/d） and powder on the structure of porous Ti and the formation mechanisms of big holes and small holes are investigated. The results demonstrate that when the experiment is 95 % Ti＋5 % TiH2 （95 %, 5 % are mass fractions） and D/d = 1, porous titanium holes are comprised of big holes and small holes, small holes make part of the big holes connected, to be there-dimensional connectivity structure. Laser beam irradiates preset powder selectively, and the area without irradiated form big holes. Big holes are decided by D/d. Big holes are formed under D/ d = l, while under D/d = 2, are not. Till2 is decomposed and produces H2 under the irradiation of laser beam, with the rapid solidification and ＂Piston Effect＂, and some H2 does not have enough time to overflow from weld pool and thus form small holes; the effect of small holes on porosity is not obvious, but the existence of small holes improve the open ratio of the samDle dramatically.

关 键 词：激光技术 激光选择熔化成形 多孔钛 孔结构 

分 类 号：TG456.7[金属学及工艺—焊接]