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首先,以15vol%或25vol%的TiC0.5N0.5粉体为导电第二相,利用热压烧结法制备了TiC0.5N0.5/Si3N4复相陶瓷;然后,分别通过物理气相沉积(PVD)和化学气相沉积(CVD)技术在TiC0.5N0.5/Si3N4陶瓷刀具表面沉积了CrAlN和TiN/Al2O3/TiN涂层;最后,通过对TiC0.5N0.5/Si3N4刀具进行连续切削灰铸铁实验,研究了TiC0.5N0.5含量和涂层类型对刀具磨损特征的影响,并探讨了刀具的磨损机制。结果表明:TiC0.5N0.5含量的增加有利于提高TiC0.5N0.5/Si3N4复相陶瓷刀具基体的硬度和电导率,但对耐磨性和切削寿命的影响较小;采用PVD技术沉积CrAlN涂层时,随着TiC0.5N0.5含量的增加,涂层的厚度、结合强度和硬度都得到提高,涂层刀具的磨损性能显著提高,切削寿命也明显延长;而采用CVD技术沉积TiN/Al2O3/TiN涂层时,TiC0.5N0.5含量的变化对涂层的厚度、结合强度和硬度基本没有影响,TiN/Al2O3/TiN涂层刀具整体切削性能变化不大。CrAlN涂层和TiN/Al2O3/TiN涂层都可明显改善TiC0.5N0.5/Si3N4复相陶瓷刀具的耐磨性和切削寿命;相对于TiN/Al2O3/TiN涂层,CrAlN涂层具有更高的涂层硬度和粘着强度,但TiN/Al2O3/TiN涂层具有较大的涂层厚度,TiN/Al2O3/TiN涂层刀具表现出更加优异的耐磨性和切削寿命。TiC0.5N0.5/Si3N4复相陶瓷刀具的磨损机制以机械摩擦导致的磨粒磨损为主,伴随有少量的粘结磨损。
First, TiC0.5N0.5 / Si3N4 composite ceramics were prepared by hot-press sintering with 15vol% or 25vol% TiC0.5N0.5 powders as the conductive second phase. Then, the samples were separated by physical vapor deposition (PVD) And TiC0.5N0.5 / Si3N4 ceramic tools by chemical vapor deposition (CVD) technology. Finally, the TiC0.5N0.5 / Si3N4 tool was cut by the continuous cutting of gray cast iron, The effect of TiC 0.5N 0.5 content and coating type on tool wear characteristics was studied and the wear mechanism of the tool was also discussed. The results show that the increase of TiC0.5N0.5 content is beneficial to improve the hardness and electrical conductivity of TiC0.5N0.5 / Si3N4 composite ceramic tool substrate, but has little influence on the wear resistance and cutting life. The PVD technique is used to deposit CrAlN With the increase of TiC0.5N0.5 content, the thickness, the bonding strength and the hardness of the coating are increased, the wear performance of the coating tool is significantly improved, and the cutting life is also significantly prolonged. However, the deposition of TiN / In the case of Al2O3 / TiN coating, the variation of TiC0.5N0.5 content had no effect on the thickness, bond strength and hardness of the coating, and the overall cutting performance of the TiN / Al2O3 / TiN coating did not change much. CrAlN coating and TiN / Al2O3 / TiN coating can significantly improve the wear resistance and cutting life of TiC0.5N0.5 / Si3N4 composite ceramic tool; CrAlN coating has higher relative to TiN / Al2O3 / TiN coating However, TiN / Al2O3 / TiN coatings have larger coating thickness and TiN / Al2O3 / TiN coated tools exhibit more excellent wear resistance and cutting life. The wear mechanism of TiC0.5N0.5 / Si3N4 composite ceramic tool is mainly abrasive wear caused by mechanical friction, accompanied by a small amount of bond wear.