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采用IPG光纤激光加工系统及预置粉末法,在Cr12MoV钢表面激光熔覆了Co/MoS_2/CaF_2自润滑复合涂层。利用X射线衍射(XRD)、扫描电镜(SEM)和能谱仪(EDX)等研究了Co/MoS_2/CaF_2自润滑复合涂层微观组织及摩擦学行为。结果表明,涂层组织为致密的网状结构,局部表现出枝晶生长的特征,熔覆涂层与基体为冶金结合。熔覆涂层中存在MoS_2和CaF_2,部分MoS_2和CaF_2在激光热作用下发生了分解,分解后的S、Ca等元素与Co元素生成了CoF_3和CaS等新相。常温条件下,润滑相含量为a(MoS_2)=7.5%、a(CaF_2)=7.5%的激光熔覆自润滑涂层减摩效果明显,摩擦系数为0.20~0.35。
The laser cladding of Co / MoS_2 / CaF_2 self-lubricating composite coating on the surface of Cr12MoV steel was carried out by IPG fiber laser processing system and preset powder method. The microstructure and tribological behavior of Co / MoS_2 / CaF_2 self-lubricating composite coatings were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDX) The results show that the microstructure of the coating is a dense network structure, the local dendrite growth characteristics, cladding coating and the substrate for metallurgical bonding. MoS 2 and CaF 2 exist in the overlay. Some MoS 2 and CaF 2 decompose under the action of laser heat. The decomposed S and Ca elements and Co elements generate new phases such as CoF 3 and CaS. Under normal temperature, the tribological effect of laser cladding self-lubricating coating with a (MoS_2) = 7.5% and a (CaF_2) = 7.5% is obvious and the friction coefficient is 0.20 ~ 0.35.