中国机械工程 ›› 2015, Vol. 26 ›› Issue (12): 1645-1651.

• 科学基金 • 上一篇    下一篇

CBN-WC-10Co刀具材料的电火花线切割机理

毛聪1,2;孙小丽1,2;卢继1,2;张健1,2   

  1. 1.长沙理工大学,长沙,410114
    2.工程车辆安全性设计与可靠性技术湖南省重点实验室,长沙,410114
  • 出版日期:2015-06-25 发布日期:2015-06-29
  • 基金资助:
    国家自然科学基金资助项目(51375061);湖南省教育厅科学研究项目(13K054);长沙市科技计划资助项目(K1308035-11) 
    National Natural Science Foundation of China(No. 51375061);
    Hunan Provincial Science Research Program of Ministry of Education of China(No. 13K054)

On  Cutting  Mechanism  of  CBN-WC-10Co  Composite   Cutting   Tool  Material  with   WEDM

Mao Cong1,2;Sun Xiaoli1,2;Lu  Ji1,2;Zhang Jian1,2   

  1. 1.Changsha University  of  Science  &  Technology,Changsha,410114
    2.Key  Laboratory  of  Safety  Design  and Reliability  Technology for Engineering Vehicle,Hunan Province,Changsha,410114
  • Online:2015-06-25 Published:2015-06-29
  • Supported by:
     
    National Natural Science Foundation of China(No. 51375061);
    Hunan Provincial Science Research Program of Ministry of Education of China
    No. 13K054)

摘要:

采用电火花线切割方法对CBN-WC-10Co刀具材料进行了线切割加工实验,利用带能谱分析的扫描电子显微镜(SEM)观察了切割试件截面和表面的显微形貌并进行了成分分析。从微观角度分别研究了CBN颗粒和硬质合金基体的材料去除机理,分析了CBN-WC-10Co刀具材料的电火花线切割热损伤情况。研究结果表明:CBN-WC-10Co刀具材料的电火花线切割材料去除机理主要是通过放电通道产生的高温使材料局部区域熔化或者气化,在放电爆炸力作用下被抛出熔池,同时放电爆炸力使部分CBN颗粒直接从硬质合金基体脱落,形成凹坑;黏结剂金属钴因其导电性好、熔点和沸点低而容易被过量去除,导致WC颗粒因失去支撑结构而从表层脱落,且放电通道内产生的爆炸冲击波也会造成WC边缘局部碎裂。

关键词: CBN-WC-10Co, 刀具材料, 电火花线切割;材料蚀除机理, 热损伤

Abstract:

Traditional machining was unsuitable for CBN-WC-10Co composite cutting tool material due to its  perfect toughness,high hardness and excellent abrasive resistance.WEDM  was   an  effective method for  the cutting tool material because of the unique advantages.Experiments on WEDM of CBN-WC-10Co  composite cutting tool material were carried out.The surface properties of WEDM specimens were analyzed by scanning electron microscopy(SEM).The material removal mechanism and thermal damage of CBN-WC-10Co were discussed.The study  indicates that the material removal mechanism with WEDM  is  mainly due to the extremely high temperature generated by the discharge channel which makes the local material melt or gasification,and  the products are thrown out under the action of discharge explosive  force.Meanwhile,the discharge explosive force  makes  part of  CBN  particles directly  fall off from the cemented carbide and forms  pits.Cobalt is easy to  over-removal for the good conductivity,low melting point and boiling point,and  then WC  particles  always  drop  from  the  surface  owing to the losing of the supporting structure.The shock wave generated in the discharge channel can also cause the appearance of the local crack at WC grains edge.

Key words: CBN-WC-10Co composite;cutting tool material;wire , electrical discharge machining(WEDM);material , removal mechanism;thermal damage

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