激光热喷涂Co30Cr8W1.6C3Ni1.4Si涂层在PAO+2.5%MoDTC油中摩擦学特性

Tribological Characteristics of Laser Thermal Sprayed Co30Cr8W1.6C3Ni1.4Si Coating in PAO+2.5%MoDTC Oil

摘要:

为了提高TC4合金的耐磨性能，采用激光热喷涂技术在其表面制备了Co₃₀Cr₈W_1.6C₃Ni_1.4Si涂层。通过扫描电子显微镜（SEM）和X射线衍射（XRD）分析了涂层的形貌和物相，并通过摩擦磨损实验研究了涂层在PAO+2.5%MoDTC（质量分数）油中的磨损行为。结果表明，激光热喷涂的Co₃₀Cr₈W_1.6C₃Ni_1.4Si涂层主要由Ti、WC_1-x、CoO、Co₂Ti₄O和CoAl相组成，在涂层界面形成冶金结合。在激光功率为1000、1200和1400 W时所制备的涂层平均摩擦因数分别为0.151、0.120和0.171，其对应的磨损率分别为1.17×10^-6、1.33×10^-6和2.80×10^-6 mm³?N^-1?m^-1，磨损机理为磨粒磨损，其枝晶尺寸对降磨起主要作用。

Abstract:

To elevate the wear resistance of TC4 alloy, Co₃₀Cr₈W_1.6C₃Ni_1.4Si coating was fabricated on the surface by laser thermal spraying (LTS). The morphologies and phases of obtained coatings were analyzed by scanning electronic microscope (SEM) and X-ray diffraction (XRD), respectively. The friction and wear properties of the coatings in poly-alpha-olefin (PAO)+2.5wt% molybdenum dithiocarbamate (MoDTC) oil were investigated by wear tester. The results show that the laser thermal sprayed Co₃₀Cr₈W_1.6C₃Ni_1.4Si coatings are primarily composed of Ti, WC_1-x, CoO, Co₂Ti₄O and CoAl phases, and the metallurgical bonding forms at the coating interface. The average coefficient of friction (COF) of Co₃₀Cr₈W_1.6C₃Ni_1.4Si coatings fabricated at the laser power of 1000, 1200 and 1400 W is 0.151, 0.120, and 0.171 with corresponding wear rate of 1.17×10^-6, 1.33×10^-6 and 2.80×10^-6 mm³·N^-1·m^-1, respectively, which increases with the increase of laser power. The wear mechanism is abrasive wear, and the dendrite size is the dominant role of anti-wear.