【摘要】 利用光学显微镜、扫描电镜和透射电镜对不同粒度等离子旋转电极雾化(PREP)FGH4096合金原始粉末的凝固组织和碳化物进行研究。分析结果表明:随着粉末粒度的减小,粉末表面和内部依次呈现枝晶、欠发达的枝晶和胞晶组织,枝晶臂与枝晶轴之间元素含量的差距逐渐减小。随着冷速递减,花状碳化物直径逐渐增大,枝晶间碳化物中强碳化物形成元素的质量分数和晶格常数减小。而不同尺寸粉末中枝晶臂碳化物的成分及晶格常数则无明显差别。更多还原

【Abstract】 Optical microscope, scanning electron microscope and transmission electron microscope were used to investigate the microstructure of plasma rotating electrode processing(PREP) powders with different size. The results show that the solidification microstructures of particle are change from dendrite in major to cellular and the segregation is lightened with decreased particle size. The relational expression of particle size with cooling rate and secondary arm dendrite are obtained. The sizes of petal MC′ are getting larger, mass fraction of strong carbide-forming elements(Nb, Ti, Zr) and lattice parameters are increased.更多还原