自熔合金粉末性能对喷焊涂层组织的影响

利用扫描电镜SEM和X射线衍射仪分析研究了自熔合金粉末颗粒内部形貌和夹杂物对涂层组织的影响.结果表明,在空心粉率相同的情况下,空心粉末中气泡在中心形成,内部壁厚均匀且较厚的粉粒比颗粒内部气泡出现偏移或开口的粉粒更易产生喷焊涂层微观缺陷(针孔);粉末颗粒内部存在着少量金属Cr夹杂,由于夹杂物表面生成了保护性氧化膜,喷焊时夹杂物不能溶解到基体中,涂层在进行磨削加工时出现剥离,形成不规则状缺陷.

Influence of property of self-fusible alloy powders on coating microstructure

Influence of inner morphologies and inclusion of self-fusible alloy powders on the microstructure of coating is investigated by means of scanning electron microscopy (SEM) and X-ray diffraction meter(XRD). The investigation results indicate that, for the identical hollow particles ratio, micro-flaw, i.e., the needle holes in coatings are more easily formed for the powder particles with a central air bubble and a thicker uniform wall than for those with excentral or open air bubbles; there is little amount of chrome inclusion in the interior of powder particles to form a sort of protective oxidation film on the wall and it can not melt into the matrix while the coating is being sprayed, so that the coatings will peel off to produce irregular flaws while the coating is being ground.