硬质合金加工刀具的表面涂层及性能研究

Study on the surface coating and properties of carbide cutting tools

采用磁控溅射的方法在硬质合金加工刀具表面制备了AlCrN、TiAlSiN和TiAlCrN涂层,对比分析了3种涂层的表面形貌、涂层厚度、表面粗糙度、硬度、与基体结合力和耐磨性能。结果表明,硬质合金加工刀具的3种涂层表面都可见尺寸不等的显微凹坑与白色颗粒存在,TiAlSiN涂层的厚度相对较小、粗糙度相对较大;3种涂层的显微硬度都明显高于基体,且显微硬度从高至低顺序为:AlCrN>TiAlCrN>TiAlSiN;AlCrN、TiAlSiN和TiAlCrN涂层与基体的结合力分别为44、39和48N。3种涂层试样的摩擦因数都小于基体试样,且相同载荷下的磨损率都明显小于基体试样,磨损率从小至大为AlCrN<TiAlCrN<TiAlSiN;室温摩擦磨损条件下,3种涂层抵抗摩擦磨损的能力都高于基体材料,且AlCrN涂层具有最佳的耐磨性能,其磨损机理为氧化磨损和磨粒磨损。

AlCrN,TiAlSiN and TiAlCrN coatings were prepared on the surface of cemented carbide cutting tools by magnetron sputtering.The surface morphology,coating thickness,surface roughness,hardness,adhesion with matrix and wear resistance of the three coatings were compared and analyzed.The results show that there are micro pits with different sizes and white particles on the surface of three kinds of coatings of cemented carbide cutting tools,while the thickness of TiAlSiN coating is relatively small and the roughness is relatively large;the microhardness of the three kinds of coatings is obviously higher than that of the matrix,and the order of the microhardness from high to low is:AlCrN>TiAlCrN>TiAlSiN;The adhesion of AlCrN,TiAlSiN and TiAlCrN coatings to the substrate were 44,39 and 48 N,respectively.The friction coefficient of the three kinds of coating samples is smaller than that of the uncoated samples,and the wear rate under the same load is significantly smaller than that of the matrix,and the wear rate of the coating is from small to large as AlCrN<TiAlCrN<TiAlSiN;under the condition of friction and wear at room temperature,the resistance of the three kinds of coating to friction and wear is higher than that of the base material,and the AlCrN coating has the best wear resistance,and its wear mechanism is oxidation wear and abrasive wear.