40Cr钢化学镀Ni-W-P/PTFE自润滑镀层的耐磨性能

Wear resistance properties of Ni-W-P/PTFE self-lubricating coating on 40Cr steel by electroless plating

为改善40Cr钢的耐磨性,采用化学镀工艺在40Cr钢表面制备Ni-W-P/PTFE自润滑镀层。研究PTFE乳液含量对镀层中PTFE微粒含量及镀层厚度、表面粗糙度、显微硬度和耐磨性的影响,分析了40Cr钢和镀层的磨损机制。结果表明:随PTFE乳液质量浓度从15 g/L增至75 g/L,镀层中PTFE微粒的质量分数从1.92%升至3.88%,镀层厚度和表面粗糙度相差不大,显微硬度总体下降,耐磨性改善。随PTFE乳液质量浓度从75 g/L增至105 g/L,镀层中PTFE微粒含量下降,镀层表面平整度变差,显微硬度降低,耐磨性下降。40Cr钢的磨损机制主要为磨粒磨损、轻度黏着磨损和较严重氧化磨损,而Ni-W-P/PTFE自润滑镀层的磨损机制主要为磨粒磨损和轻度氧化磨损。PTFE乳液质量浓度为75 g/L制备的NiW-P/PTFE自润滑镀层耐磨性优于其它Ni-W-P/PTFE自润滑镀层,可有效改善40Cr钢的耐磨性。

Ni-W-P/PTFE self-lubricating coating was prepared on the surface of 40 Cr steel by electroless plating in order to improve the wear resistance of 40 Cr steel.The effects of mass concentration of PTFE emulsion on the mass fraction of PTFE particles in the coating,and the thickness,surface roughness,microhardness and wear resistance of the coating were studied,and the wear mechanism of 40 Cr steel and coating was analyzed.The results show that as the mass concentration of PTFE emulsion increases from 15 g/L to 75 g/L,the mass fraction of PTFE particles in the coating increases from 1.92%to 3.88%,the thickness and surface roughness of the coating are not significantly different,the microhardness shows a downward trend and the wear resistance gradually improves.However,as the mass concentration of PTFE emulsion increases from 75 g/L to 105 g/L,the mass fraction of PTFE particles in the coating decreases,the surface roughness of the coating deteriorates,and the microhardness decreases,leading to a decline in wear resistance.The wear mechanisms of 40 Cr steel are mainly abrasive wear,slight adhesive wear and severe oxidation wear,while the wear mechanism of Ni-W-P/PTFE self-lubricating coating is mainly abrasive wear and slight oxidation wear.The wear resistance of Ni-W-P/PTFE self-lubricating coating prepared with PTFE emulsion 75 g/L is better than that of other Ni-W-P/PTFE self-lubricating coating,which can effectively improve the wear resistance of 40 Cr steel.