Cr/x/DLC复合涂层刀具切削铝硅合金切削性能研究

Experimental study of cutting performance in machining of aluminum-silicon alloy with Cr/x/DLC composite coating tools

类金刚石(Diamond-Like Carbon,DLC)涂层刀具结合了基体强度高、韧性好以及涂层硬度高、耐磨性高的优点,可以有效降低刀-屑间摩擦,提高刀具切削寿命和加工效率。采用直流磁控溅射和等离子体辅助化学气相沉积(Plasma-Assisted Chemical Vapor Deposition,PACVD)法分别在硬质合金刀具基体上制备了单一DLC涂层、Cr/W-DLC/DLC复合涂层和Cr/CrN/DLC复合涂层。对比研究了具有不同Cr/x/DLC过渡层的DLC复合涂层硬质合金刀具加工过共晶结构铝硅合金AC9B的切削性能。研究结果表明:切削铝硅合金时,相对于无涂层硬质合金刀具,DLC涂层硬质合金刀具可以明显降低切削力和切削温度,并且具有更长的刀具切削寿命;Cr/W-DLC/DLC复合涂层硬质合金刀具的切削力最小,切削寿命最长。经显微分析,发现DLC涂层硬质合金刀具切削铝硅合金时的磨损机理主要是黏结磨损和硬质点磨损。

Diamond-Like Carbon(DLC)coating tools combine the advantages of high strength,good toughness of substrate and high hardness and wear resistance of the coating,which can effectively reduce the tool-chip friction and improve tool life and processing efficiency.Monolayer DLC coating,Cr/W-DLC/DLC composite coating and Cr/CrN/DLC composite coating were prepared respectively on the cemented carbide substrate by DC magnetron sputtering and Plasma-Assisted Chemical Vapor Deposition(PACVD).The cutting performances of DLC coating cemented carbide with different Cr/x/DLC transition interlayers for cutting of hypereutectic Al-Si alloy AC9B were compared.The results show that when cutting Al-Si alloy,DLC coating cemented carbide tools can significantly reduce cutting force,cutting temperature and have a longer tool life than uncoated cemented carbide tools.The cemented carbide tools with Cr/W-DLC/DLC composite coating have the smallest cutting force and the longest tool life.Microscopic analysis revealed that the wear mechanism of DLC coating cemented carbide tools for cutting Al-Si alloys is mainly adhesion wear and hard particle wear.