基于耐磨性的聚晶金刚石刀具热损伤研究

Study on Thermal Damage of Polycrystalline Diamond Tools Based on Wear Resistance

为了研究PCD刀具钎焊热损伤程度对耐磨性的影响,设计单因素试验探究恒温时间、钎焊温度对热损伤的影响规律,定量分析热损伤程度对耐磨性的影响。结果表明:钎焊温度和恒温时间对PCD刀具的热损伤影响显著,其中钎焊温度对热损伤影响最大;PCD刀具钎焊过程中结合剂Co及其氧化物脱落形成的凹坑会降低刀具耐磨性,当产生穿晶裂纹和沿晶裂纹两种热损伤形式时,刀具耐磨性急剧降低;PCD刀具耐磨性较热损伤程度更为敏感,其变化率至少是热损伤变化率的1.2倍。

For searching the influence of the degree of thermal damage on the wear resistance of PCD tool brazing,a single factor experiment is designed to investigate and quantitatively analyze the influence of constant temperature time and brazing temperature on the thermal damage.The results show that:brazing temperature and constant temperature time have a significant effect on the thermal damage of PCD tools,in which the brazing temperature has the greatest effect on the thermal damage.The pits formed during the brazing process of PCD tools by the detachment of the bonding agent Co and its oxides reduce the tool wear resistance.Tool wear resistance is further reduced when pits and surface cracks occur in diamond abrasives.The wear resistance of PCD tools is more sensitive to its degree of thermal damage,and its rate of change is at least 1.2 times that of the degree of thermal damage.