摘要
对PCBN刀具车削铸造高温合金K423A进行了切削试验研究及有限元仿真研究,观察和分析了刀具的磨损/破损形态,并从应力场和温度场分布的角度对刀具的失效机理进行了深入分析。在四种不同的切削条件下,主切削刃的失效形式主要为刀具材料的剥落和粘结磨损;在切削速度60m/min时,PCBN刀具容易发生破损;随着切削速度的增加,副切削刃的磨损/破损带宽度减小。切削速度的提高引起切削温度的增加,使得工件材料的强度降低,同时刀具脆性降低而韧性增加,这是副后刀面破损减少的可能原因之一。采用修正的莫尔理论对有限元仿真结果中刀具复杂的应力状态进行分析,推断了刀具材料破坏的起始位置。
Cutting tests and finite element modeling of PCBN tools when turning cast superalloy K423A are studied, tool breakage and tool wear behaviors are observed and analyzed. Moreover, failure mechanism of PCBN tools is further investigated from the perspective of stress distribution and temperature contours. Under four different cutting conditions, flaking of tool material and adhesive wear are observed on tool major cutting edge. Under cutting speed of 60m/min, the PCBN tool is prone to breakage; with the increase in cutting speed, the width of tool wear/breakage on tool minor cutting edge is reduced. The cutting temperature rises as the increase of cutting speed, leading to the reduced workpiece material strength, the reduced cutting tool brittleness and the increased toughness. This is one of the possible causes of damage re- duction on minor flank. The modified Mohr criterion is used to analyze the complex stress contours of the PCBN tool, and then the starting position of the tool material failure is inferred.
出处
《工具技术》
北大核心
2015年第1期11-16,共6页
Tool Engineering
基金
高档数控机床与基础制造装备国家科技重大专项(2014ZX04012012)
教育部基本科研业务费资助项目
