摘要
采用激光熔覆技术 ,在 4 5 # 钢表面进行了镍基合金粉末添加TiO2 的熔覆试验。通过对激光熔覆工艺参数及TiO2 含量的优选可以获得质量良好的熔覆层。对激光熔覆层横断面进行了显微硬度测量和显微组织分析 ,对熔覆层表面进行了X射线衍射 (XRD)物相分析及摩擦学性能测试。试验表明 ,当TiO2 含量 3wt . %～ 4wt . % ,激光功率 1 8kW ,扫描速度 2～ 4mm/s时 ,可以获得无裂纹、无气孔且与基底呈冶金结合的质量良好的熔覆层。TiO2 能够提高镍基合金熔覆层的韧性、耐磨性 ,细化熔覆层的组织 ,降低熔覆层的裂纹敏感性。TiO2 对G112镍基合金激光熔覆层的改善归因于TiO2 对熔覆层组织的均匀细化。
The experiments of laser cladding of Ni-base composite alloy powder doped with TiO2 were carried out. Various laser processing parameters and different TiO2 content were chosen to obtain a perfect clad layer. The microstructure observation and microhardness test of the cross-section of the laser cladding zone were performed. X-ray diffraction analysis and tribotesting of the surface of the laser coatings were also accomplished. A good finished and crack- and porosity-free surface clad layer was obtained with the TiO2 content of 3 wt.-% - 4 wt.-% at the beam scanning velocity of 2 - 4 mm/s. An excelled interface between the coatings and the substrate was formed. It is shown that the addition of TiO2 can enhance the toughness of coatings, refine the microstructure of clad layer, and reduce the cracking susceptibility obviously. The improvement of properties of the laser-clad layer is due to the effect of TiO2 on it, in which TiO2 with a proper content can uniformly refine the structural grains, entirely suppress the formation of big nubbly hard-phases, greatly reduce the size of dendritic phases and increase the tenacity of coatings.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2003年第10期947-952,共6页
Chinese Journal of Lasers
基金
河南省高校创新人才基金 (1999 12 5 )
河南省杰出人才创新基金资助项目
关键词
激光技术
TIO2
激光熔覆
裂纹
耐磨性
Cracks
Microhardness
Nickel alloys
Titanium dioxide
Wear resistance
Welded steel structures
X ray diffraction analysis
