TiN涂层刀具高速车铣切削性能及磨损机理

Cutting performance and wear mechanism of TiN coat cutter in high speed turn-milling

实验研究了高速车铣D60钢时TiN涂层刀具的切削性能和磨损机理.结果表明,在水溶性冷却液浇注冷却条件下,高频交变热应力较大,涂层剥落较快,TiN涂层刀具的耐磨性较差,不能适应切削加工的要求.与此相反,干式切削时,高频交变热应力较小,虽在涂层表面有微裂纹产生,但涂层不易剥落,刀具耐磨性较好,可进行长时间稳定切削.干式切削过程中,由于机械冲击,在刀刃处产生的微小凹缺陷,是造成刀具磨损的主要原因.不论湿式切削还是干式切削,涂层剥落后,切削区产生的瞬时热量聚集将使基体粘结相软化,进而导致硬质相颗粒脱落和基体的剧烈磨损.

When D60 steel was machined by high speed turn-milling, the cutting performance and the wear mechanism of the TiN coat cutter were researched by experiment. Results show that, with water solubility cooling fluid, the high frequency alternating heat stress is heavy and the coat desquamates quickly, thus the TiN coat cutter can not meet the requirement of machining for its bad wear performance. But under the dry. condition, the high frequency alternating heat stress is light and the coat desquamates slowly, though a great deal of small chap units are formed, thus the TiN coat cutter can be used for long-time steady cutting. Under the drycondition, the main cause of the cutter wear to form tiny concave channel on the edge is machining impact. No matter in dry or wet condition, the felting phase is intenerated for the instantaneous heat collection in the cutting section, which leads to the falling of the rigid phase grains and serious abrasion of the base body.