摘要
采用光纤激光器和同步送粉技术,优化钴基高温合金在45钢基板上的激光成型工艺参数。通过SEM、EDS和XRD分析以及硬度测试,研究了不同工艺条件下该成型件的组织及硬度。结果表明:在确定的激光功率条件下,扫描速率和搭接率对激光成型钴基高温合金的微观组织和冶金缺陷有影响。提高激光扫描速率可细化晶粒,改善合金的微观组织,但扫描速率过高会增大稀释率,使组织分布不均。同时为避免重熔区出现冶金缺陷,搭接率不宜过高。钴基合金激光成型样品的微观组织主要由M_6C、Cr_(23)C_6和CrCo金属间化合物和γ-Co基体组成;激光成型工艺对该合金的硬度影响不明显,但会影响硬度分布的均匀性。
Laser forming process parameters of cobalt based superalloy on 45 steel matrix were optimized by using fiber laser and synchronous powder feeding system. The microstructure and hardnesses of the formed blocks achieved under different laser-forming process parameters were analyzed by SEM, EDS and XRD techniques and hardness tests. The results show that under certain laser power condition, laser scanning rate and overlapping rate have influences on the microstructure and metallurgical defects of laser forming cobalt based superalloy. Increasing laser scanning rate can result in grain refinement and microstructure improvement, but if the scanning rate is too high, the dilution rate increases, which makes structure distribute nonuniformly. In order to avoid the defects appearing in re-melting region, the overlapping rate should not be too high. The microstructure of laser-formed cobalt based superalloy consists of M_6C、Cr_（23）C_6,CrCo intermetallic and γ-Co matrix. The laser forming process has unapparent effects on the hardness of the alloy, but it can affect the uniformity of the hardness distribution.
出处
《热加工工艺》
CSCD
北大核心
2017年第14期40-44,共5页
Hot Working Technology
基金
国家自然科学基金项目(51371173)
辽宁省自然科学基金项目(2013024011)
关键词
激光成型工艺
钴基高温合金
显微组织
硬度
laser forming process
cobalt based superalloy
microstructure
hardness
