中文摘要：

以在飞机、汽车、轮船等领域的关键承力件上广泛应用的超高强度合金钢300M作为研究对象,采用涂层硬质合金刀具进行高速干车削加工,并对切屑变形、刀具寿命及刀具磨损机理进行分析。研究表明：高速切削300M时,切屑的塑性变形严重;涂层刀具主要的磨损形式为正常的前、后刀面磨损,以及非正常的剥落和崩刃;刀具在稳定磨损阶段形成了次生粘结层起着隔热、减摩的作用,有效提高了刀具寿命,但在急剧磨损阶段,大块状的粘结、崩刃、涂层剥落、微裂纹等致使刀具磨损加剧;高速车削300M涂层硬质合金刀具主要的磨损机理为粘结磨损、磨粒磨损、涂层剥落、微崩刃、微裂纹。该研究可望在高性能涂层刀具设计、刀具寿命预测等方面推广应用。

英文摘要：

In the work,the work piece material is ultra-high-strength alloy steel 300M which has been widely used in the key bearing parts of aircraft,automobile,ship,etc. A coated carbide tool is selected in high speed dry turning experiments. And chip deformation,tool life and wear mechanism are analyzed. The results show that the plastic deformation of the chip is serious in the high-speed turning process. The main wear forms of the coated tool are the normal rake and flank face wear,and abnormal wear,such as spalling and chipping. The secondary build-up layer is formed in the stable wear stage,which plays a role in heat insulation and friction reduction. So the tool life is improved effectively. However,the large size of bonding,chipping,coating spalling,and micro-cracks cause a high tool wear rate in the rapid wear stage. The main wear mechanisms of the coated tool involve adhesive wear,abrasive wear,coating spalling,micro-chipping and micro-crack. Hence,this work is expected to be applied in the design of high-performance coating tool and tool life prediction.