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通过等离子束表面合金化工艺用Ti-Fe合金粉末在灰铸铁表面制备了原位合成Ti C复合强化层。结果表明,合金化层厚度为350~400μm,与基体之间实现良好的冶金结合,合金化后试样表层硬度最高可达969 HV0.2,合金化区显微组织为残留奥氏体、针状马氏体和共晶莱氏体。XRD及SEM分析观察发现,在合金化区存在原位复合Ti C颗粒。通过销-盘型高温摩擦磨损试验对合金化试样和未经合金化处理的灰铸铁试样的室温及高温(473 K、673 K)下的摩擦磨损行为及机理进行了对比研究,磨损试验结果表明,合金化处理后,试样的耐磨性能相对于灰铸铁基体得到了明显改善,磨损率普遍下降3个数量级。根据扫描电镜(SEM)观察、能谱(EDS)检测和显微硬度测试分析结果可知,基体表层组织转变和Ti C颗粒是Ti C复合强化层耐磨性能提高的主要原因。
The in-situ TiC composite reinforced layer was prepared on the surface of gray cast iron by Ti-Fe alloy powder by plasma beam surface alloying. The results show that the thickness of alloying layer is 350 ~ 400μm, and the metallurgical bonding between the substrate and the substrate is good. The hardness of the sample surface after alloying is up to 969 HV0.2. The microstructure of the alloying zone is retained austenite. Like martensite and eutectic ledeburite. XRD and SEM analysis showed that in situ TiC particles existed in the alloying zone. The friction and wear behavior and mechanism of the alloyed and unalloyed gray cast iron samples at room temperature and high temperature (473 K, 673 K) were studied by pin-plate type high temperature friction and wear test. The wear test The results show that after the alloying treatment, the wear resistance of the sample is obviously improved compared with the gray cast iron substrate, and the wear rate generally drops by 3 orders of magnitude. According to the results of SEM, EDS and microhardness test, it is found that the transformation of substrate surface structure and TiC particles are the main reasons for the improvement of wear resistance of TiC composite.