电弧增材制造GH3039组织和性能研究

镍基高温合金GH3039广泛地应用于航空发动机燃烧室等零部件。采用增材制造技术制备GH3039部件可以克服其加工性能差、材料利用率低等问题。本研究首次采用基于熔化极气体保护焊的电弧增材制造（GMAW-WAAM）技术制备了GH3039薄壁件。利用光学显微镜（OM）、显微硬度仪和拉伸试验分析了薄壁构件的组织和性能。结果表明，采用GMAW-WAAM制备的GH3039构件组织致密，无气孔或裂纹等缺陷。合金的显微组织主要由高度方向生长的粗大柱状晶和层间细小晶粒构成。沉积态合金具有较好的室温和高温性能：室温抗拉强度520~540MPa，断后延伸率36~40%； 800°C抗拉强度189MPa，断后延伸率35.4%。本研究验证了采用GMAW-WAAM技术制备GH3039部件的可行性。

Microstructure and mechanical properties of GH3039 Fabricated by WAAM

GH3039 has been extensively used in aeronautic industries. Poor machinability and low material usage are common in GH3039 components, which could be resolved by frabricated by additive manufacturing. In this study, a GH3039 thin wall part was fabricated by gas metal arc welding wire arc additive manufacturing (GMAW-WAAM). Optical microscope (OM) observation, microhardness indentation and tensile tests were applied to investigate the microstructure and mechanical properties of the part. Result shows that the defect-free dense part is mainly consisted of interlayer fine grain and coarse column grain, which grew vertically. The ambient temperature ultimate tensile strength (UTS) and fracture elongation (El) of the as deposited part are 520~540MPa and 36~40%, respectively. The elevated temperature (800°C) UTS and El along the deposition direction is 189MPa and 35.4%, respectively. This study verified the feasibility of manufacturing GH3039 part by GMAW-WAAM.