摘要
在单道熔覆及薄壁墙试样制备的基础上 ,大致确定出Rene′95激光快速成形时的工艺参数和每层沉积高度 ,根据此高度对零件的CAD模型进行分层切片处理 ,生成二维平面信息 ,经过数据后处理并加入加工参数 ,生成数控信息输入成形系统 ,控制成形系统的沉积过程顺序完成各层的成形制造 ,直至加工出与CAD模型相一致的具有复杂外形的致密的金属零件。成形所用激光功率 16 0 0W ,扫描速度 3mm/s ,送粉速率 6 2g/min ,载气流量 0 3m3 /h ,所制零件总高 112mm(共沉积 380层 ) ,壁厚约 3mm ,每层沉积高度为 0 3mm ,零件具有良好的外形和尺寸精度。结果表明 :激光快速成形Rene′95镍基合金组织致密 ,成分均匀 ,沿成型高度方向具有定向凝固组织特征 ,具有较高的力学性能 但由于成型时存在很高的残余应力 ,容易导致开裂 ,通过基板预热可减缓应力。
Laser direct deposition of metallic components is a new manufacturing technology. Driven by the solid CAD model directly, fully dense metallic parts with complicated shape can be rapidly obtained through melting the coaxially fed powders with a high-power laser in a layer-by-layer manner. The processing of laser direct deposition of nickel super alloy, the obtained microstructure and properties are introduced in this paper. The results show that the as-deposited Rene'95 nickel superalloy is dense, with directional solidificationmicrostructure along the direction of deposition height. The formed materials tend to crack due to the existence of hight residual stress during deposition, preheating the base table is benefit for for residual stress reduction. By choosing the suitable processing parameters, Rene'95 nickel superalloy component with complex shape and good dimensional accuracy has been fabricated successfully.
出处
《航空材料学报》
EI
CAS
CSCD
2002年第1期22-25,共4页
Journal of Aeronautical Materials
基金
国家"973"计划 (G2 0 0 0 0 6 72 0 5 1)
关键词
激光快速成形
镍基高温合金
组织性能
激光熔覆工艺
金属零件
Computer aided design
Cracks
Deposition
Fabrication
High power lasers
Microstructure
Nickel alloys
Powders
Residual stresses
Solidification
