熔覆材料对高速钢刀具激光熔覆断屑台裂纹及硬度的影响

应用激光粉末熔覆技术，在高速钢车刀的前刀面上制备出断屑台。通过切削实验，对比普通高速钢车刀和含激光熔覆断屑台车刀的断屑效果，观察激光粉末熔覆断屑台的金相组织和形貌，测试激光粉末熔覆断屑台的热膨胀系数、物相和显微硬度。研究结果表明：具有激光熔覆断屑台的高速钢车刀，在切削过程中能够减小切屑的卷曲半径，从而使切屑更容易折断，实现有效断屑。用M2/WC-12Co粉末制作激光熔覆断屑台，能够实现激光熔覆层与高速钢基体的良好冶金结合，熔覆层无熔覆裂纹缺陷，熔覆层的硬度与高速钢车刀基体相近。M2/WC-12Co激光熔覆粉末适于制作高速钢刀具的激光熔覆断屑台。

Influences of Cladding Materials on Cracks and Hardnesses of Laser Cladding Chip Breakers on High Speed Steel Cutting Tools

Laser powder cladding technology was applied to fabricate laser cladding chip breakers on the rake faces of high speed steel(HSS) cutting tools. Through the cutting experiments, the chip breaking performances of common HSS cutting tools and cutting tools with laser cladding chip breakers were compared. The microstructures and morphologies of the laser cladding chip breakers were observed. Thermal expansion coefficient, phase composition and microhardness of laser cladding layers were measured. The experimental results show that HSS cutting tool with laser cladding chip breakers may reduce the curling radius of chips to break the chip more easily and realize an effective chip breaking during cutting processes. The laser cladding chip breakers made from M2/WC-12Co powder has metallurgical combined with HSS tool substrates. The laser cladding layers have no cracks and the hardness is similar to the substrates of HSS cutting tools. The M2/WC-12Co power is suitable for fabricating laser cladding chip breakers of HSS cutting tools.