离心铸造工艺制备WC颗粒增强钢基回转体零件研究

Study on WC Particles Reinforced Steel Matrix Revolving Parts Prepared by Centrifugal Casting

通过改进现有悬臂式离心铸造机,成功制备了外径200 mm、内径140 mm、长150 mm的碳化钨颗粒增强钢基回转体复合材料。分析了增强颗粒在离心铸造中的受力情况,推出液态金属中的颗粒在离心力场下的运动规律。采用光学显微镜、扫描电镜和X射线衍射,分析了复合层中碳化钨颗粒的分布规律,以及复合层的物相组成。结果表明,碳化钨颗粒体积分数在复合层中由内向外逐渐增加,其表层碳化钨颗粒复合层厚度约5 mm,颗粒与基材结合良好,没有夹杂、裂纹等缺陷;颗粒与颗粒之间无缠结团聚现象;颗粒周围部分溶解,复合层中存在Fe3W3C相,颗粒与基材间形成冶金结合。

WC particles reinforced steel matrix revolving composite material with 200 mm external diameter,140 mm internal diameter,and 150 mm in length was successfully prepared on a improved cantilever centrifugal casting machines.On the basis of analyzing the law of movement and distribution of reinforce particles in molten metal,the movement model of particles in melt was established under centrifugal field.WC particles distribution law and the phase in composite layer was analyzed by optical microscope,canning electron microscopy and x-ray diffraction.The results show that the volume percentage of the WC particles in the composite layer increased gradually from inside to outside,the thickness of surface particles reinforced layer was about 5 mm,the combined-interface between composite layer and matrix transit smoothly,the particles combined well with each other,without any impurities and cracks;there were no massing phenomena between particles;the particles are partly dissolved,there are Fe3W3C exited in composite layer,the particles and base material are combined by chemical reactions.