摘要
为提高Ni-SiC复合镀层的耐磨性,采用脉冲电沉积的方法,在Q235钢表面上制备了Ni-纳米SiC复合镀层,利用扫描电镜(SEM)、X射线衍射仪(XRD)、显微硬度计及摩擦磨损试验机等分析了单个工艺条件对Ni-SiC复合镀层显微硬度和耐磨性的影响规律,观察、测试、比较了纯Ni镀层和Ni-SiC复合镀层的表面形貌和摩擦磨损性能。结果表明:随着纳米SiC粒子浓度在3~13g/L范围内逐渐增大,镀层的硬度先升高后降低,磨损量逐渐下降;随着平均电流密度在1~6A/dm^2之间逐渐增加,镀层的硬度先升高而后下降,磨损量先减少后增加;随着占空比在10%~60%范围内逐渐增加,镀层的硬度逐渐下降,磨损量逐渐升高。纯镍镀层组织较疏松,晶粒比较粗大,当SiC浓度为9g/L、电流密度为4A/dm^2、占空比为10%时,Ni-SiC复合镀层组织致密,SiC粒子分布均匀,其磨损量相对纯镍镀层减少了4倍以上。
Ni/nano-SiC composite coating was prepared on Q235 steel surface by pulse electrodeposition. Scanning electron microscope( SEM),X- ray diffractometer( XRD),microhardness tester and tribometer were used to study the influences of process conditions on the microhardness and wear resistance of Ni/nano-SiC composite coating,and the surface morphology and tribological property of pure Ni coating and Ni/nano-SiC composite coating were observed,tested and compared. Results showed that as the concentration of SiC nanoparticles increased in the range of3 ~ 13 g/L,the hardness of coating increased firstly and then decreased,while the abrasion loss decreased gradually. With the increase of current density in the range of 1 ~ 6 A/dm^2,the hardness of coating increased firstly and then decreased,while the abrasion loss increased gradually. When the duty ratios were enhanced in the range of 10% ~ 60%,the hardness of coating decreased and the abrasion loss increased slowly. Besides,the organization structure of pure Ni coating was looser and the crystal particles were larger. When the concentration of SiC was 9 g/L,the current density was 4 A/dm^2 and the duty ratio was 10%,the Ni/nano-SiC composite coating had compact organization and uniform distribution of SiC particles,and its abrasion loss reduced 4times than that of pure Ni coating.
出处
《材料保护》
CAS
CSCD
北大核心
2016年第2期10-13,6,共4页
Materials Protection
