摘要
利用强激光模拟实验 ,对硬质合金刀具在端铣过程中的温度变化规律进行了模拟。扫描电镜分析结果显示 ,热源的热冲击会产生以热源为中心的径向裂纹。实验中发现 ,裂纹萌生寿命、每一次冲击所引起的裂纹长度的增加量 ,以及裂纹总数量的增加都具有相当大的随机性。刀具中原有缺陷的随机性和不同区域微观性能的随机性是引起热裂纹萌生和扩展随机性的主要原因。有限元法分析的结果表明 ,在最高温度为 1 0 0 0℃时 ,最大热拉应力小于材料的抗拉强度 ,而最大热剪应力较大 ,因此 。
The actual milling temperature regularities of cemented carbide tools are studied by high-power laser simulation. It is found by SEM observation that a number of cracks are generated in the vicinity of the heating point. The majority of the cracks is in the radial direction with the heating point as the center. Every aspect of the thermal cracking process, including the crack initiation life, crack size increment and the total number of cracks generated, reveals a stochastic feature, which is obviously caused by the stochastic characteristics of the initial defects and the variations of the properties in different regions of the tool tip. The results from finite element analysis suggest that the maximum shear stress theory can be used as the criterion for thermal cracking of cemented carbide tools under the highest temperature of 1000℃, considering that the maximum thermal tensile stress is less than the ultimate tensile strength of the material and the maximum shearing stress is fairly large.
出处
《中国机械工程》
CAS
CSCD
北大核心
2001年第6期707-709,共3页
China Mechanical Engineering
基金
国家自然科学基金资助项目 (5 9975 0 5 4)
山东省优秀中青年科学家科研奖励基金资助项目 (9812 )
关键词
硬质合金刀具
热破损
裂纹
激光
模拟
cemented carbide tool thermal cracking crack laser simulation
