高温合金GH4169电子束熔丝增材制造工艺研究

目的 研究GH4169合金电子束熔丝增材制造过程中电子束流参数的选择方法及组织特征.方法 在其他工艺参数不变的条件下,分析电子束流的大小对单层成形形貌的影响,寻找最佳电子束流参数值;采用光学显微观察增材制造GH4169合金柱状晶组织.结果 获得了不同电子束流条件下,单熔覆层表面形貌、横截面形貌、熔覆宽度和高度数据,以及GH4169合金柱状晶形貌.结论 在一定范围内,随着电子束流值增加,熔覆层宽度增加而高度减小,但电子束流增加到一定值时,熔覆宽度及高度的变化幅度明显降低,在综合考虑熔覆层表面形貌和横截面形貌的基础上确定了电子束流最佳参数值;增材制造GH4169合金组织为沿沉积高度方向外延生长的柱状晶,柱状晶方向与竖直方向呈现出一定的偏角.

Study on Process for Electron Beam Wire-Feed Additive Manufacturing of GH4169 Superalloy

The paper aims to study the selection method of electron-beam current value and microstructure characteristics during additive manufacturing of GH4169 alloy. The effect of electron-beam current value on the morphology of single layer deposition was analyzed under the condition of the same other process parameters, in order to search for the most favorable parameters of electron beam current. The columnar crystal microstructure of GH4169 alloy was observed by optical microscope. The surface morphology, cross-section morphology, fused deposition width and height data of single deposition layer were obtained under different electron beam conditions. The columnar crystal characteristics of GH4169 alloy was analyzed. In a certain range, with the increase of electron beam current, the deposition layer width increased and its height decreased. However, the variation range of deposition width and height dropped sharply as the value of electron beam reaches a certain threshold. The optimum parameter of electron beam current was determined considering the surface morphology and cross-section morphology of the deposition layer. The microstructure of GH4169 alloy fabricated by additive manufacturing was mainly composed of epitaxial columnar crystal growing along the deposition height. There is a certain angle between the direction of columnar crystal and the vertical direction.