冷却润滑介质对钛合金Ti6Al4V加工性能的影响(英文)

EFFECT OF COOLING/LUBRICATION MEDIUM ON MACHINABILITY OF Ti6Al4V

为了更好地理解和认识冷却润滑介质在切削过程中的作用并延伸它们的应用,应用无涂层硬质合金对钛合金Ti6Al4V在不同冷却润滑介质下(干切削、冷风、最小量润滑(Minimal quantity lubrication,MQL)、低温MQL以及电离空气)进行了高速车削试验。结果表明,在120m/min车削Ti6Al4V时,电离空气条件下的切削力最小,低温MQL条件下切削温度最低。电离空气条件下的刀具寿命最长,其次是低温MQL。同时,电离空气条件下获得的加工表面粗糙度最小。通过扫描电镜分析,高速车削Ti6Al4V时,后刀面磨损和月牙洼磨损是刀具磨损的主要方式。实验说明电离空气与低温MQL具有较好的冷却与润滑效果,可以有效地提高刀具寿命。

To better understand and know the roles of cooling/lubrication medium in the cutting process and expand their applicability,uncoated cemented carbide tools are used in high-speed turning Ti6Al4V.Dry,cold air,minimal quantity lubrication（MQL）,cryogenic MQL,and ionized air as the cooling/lubrication conditions are studied.Experimental results show that at speed 120 m/min turning Ti6Al4V,the cutting force under ionized air is smallest under all lubricant conditions,and tool life is best,next is cryogenic MQL.MQL and cold air almost have the same effect,a little better than dry.Meanwhile the smallest surface roughness is also obtained under ionized air condition.Flank wear and crater wear are the dominant failure modes when high-speed turning Ti6Al4V by SEM analysis.Finally the conclusion is drawn that ionized air and cryogenic MQL have better cooling/lubrication effects and can effectively improve the tool life.