PREP 工艺制取镍基高温合金粉末中的异常颗粒

Study on abnormal particles in Ni-base Superalloy Powder by PREP Process

摘要:

摘 要: 等离子旋转电极制粉工艺（PREP）是目前我国制取高温合金粉末的重要手段之一。粉末的质量是粉末冶金领域备受关注的问题。本研究对PREP工艺制取镍基高温合金粉末中的一种异常颗粒进行了观察、分类、统计和分析。研究结果表明，合金粉末中存在粉末与升华物、熔渣、陶瓷、有机物粘连为一体的异常颗粒。这类异常颗粒的产生与母合金的纯净度、夹杂的性质、雾化制粉工艺参数有密切的关系。筛分和静电处理异常颗粒的能力与所粘连夹杂物的尺寸、形态以及化学组成和密度、介电常数等物理性质有关。与筛分处理相比，静电后1kg粉末样品中粘连夹杂的颗粒减少了63%；在50-150μm的成品粉中，粘连熔渣的颗粒占残存夹杂物总量的36%，粘连陶瓷颗粒为4%，粘有机物颗粒占11%。

Abstract:

Abstract: Plasma Rotating Electrode Process (PREP) is one of the most important methods of manufacturing superalloy powder in China. The quality of powder is highly concerned in the field of Powder Metallurgy(PM). One kind of abnormal particles in nickel-based superalloy powder by PREP was observed, classified, and analyzed statistically in this paper. Research has shown that the abnormal particles which consist of powder and adhering sublimation, slag, ceramic and organic impurities exist in the superalloy powders. The formation of abnormal particles has a close relationship with the purity of master alloys, properties of inclusions as well as powder atomization parameters. The ability of removing abnormal particles by screening and electrostatic separation was associated with the size, shape and chemical composition, physical properties(density, permittivity）of adhering inclusions. Compared with the screening process, the number of abnormal particles in 1kg powder sample reduce by 63% after electrostatic separation process. In 50-150μm finished powders, the abnormal particles adhering slag account for 36% in residual inclusions, the particles adhering ceramic -4%, the particles adhering organic-11%.