超声表面滚压处理对硬质合金组织结构及性能的影响

Effect of Ultrasonic Surface Rolling Treatment on Microstructures and Properties of Cemented Carbide

通过超声表面滚压技术(USRT)制备了具有梯度纳米结构表层的YG8硬质合金。通过X射线衍射(XRD),扫描电子显微镜(SEM)和维氏硬度计等手段表征了合金材料的微观组织结构、力学性能和在质量分数为3.5%NaCl溶液中的腐蚀行为。结果表明:滚压前后没有新相产生,当载荷为0.3 MPa、压下量为0.1 mm时,试样变形层厚度达到2.17μm,表面硬度相应提高了12.2%。此外,电化学测试结果表明,纳米晶表面在腐蚀过程中促进了钝化膜在表面上的形成,使得滚压处理后的硬质合金耐腐蚀性能得到明显增强。

YG8 cemented carbide with gradient nanostructure surface layer was prepared by ultrasonic surface rolling technology(USRT).X-ray diffraction(XRD),scanning electron microscope(SEM)and Vickers hardness tester were used to characterize the microstructure,mechanical properties and corrosion behavior of the alloy in 3.5%NaCl solution.The results show that there is no new phase before and after rolling.When the load is 0.3 MPa and the reduction is 0.1 mm,the thickness of deformation layer reaches 2.17μm,and the surface hardness increases by 12.2%.In addition,the electrochemical test results show that the corrosion resistance of cemented carbide after rolling treatment is obviously enhanced due to the formation of passivation film on the surface of nanocrystalline during the corrosion process.