AlN的添加对Ti(C,N)基金属陶瓷自配副摩擦性能的影响

Effect of AlN on the Tribological Behavior of Ti(C,N)-based Cermet Self-mated Wear Pairs

Ti(C,N)基金属陶瓷材料具有优良的耐磨耐蚀性能,被广泛应用于制造刀具、模具、轴承等各种耐磨零件,但Ti(C,N)基金属陶瓷做成的滑动轴承自配副在干式摩擦工况中却受到严重的摩擦磨损。为进一步提高Ti(C,N)基金属陶瓷材料的耐磨耐蚀性,采用粉末冶金的方法,制备不同AlN含量的Ti(C,N)基金属陶瓷,并对其抗弯强度、硬度、相对密度、磨损性能等力学性能进行测试,使用光学显微镜、扫描电镜、能谱仪对AlN加入后的试样显微组织进行观察,结果表明:当AlN加入时,Ti(C,N)基金属陶瓷形成典型的芯-环结构,随着AlN含量的增加,内环逐渐变得模糊,外环厚度逐渐变薄,晶粒的平均尺寸减小,孔隙度增加。在0~1.0%范围内,随着AlN的增加,Ti(C,N)基金属陶瓷的相对密度降低,硬度、抗弯强度略微升高,Ti(C,N)基金属陶瓷自配副干摩擦磨损性能先增加后减小,当AlN添加量为0.5%得到最优值。AlN的加入造成了晶粒细化强化,且其中固溶于粘结相中的Al元素对粘结相也有一定的强化作用,但AlN的添加使得Ti(C,N)基金属陶瓷的脱氮倾向增加,孔隙度增加,相对密度减小;当AlN加入量为0.5%,Ti(C,N)基金属陶瓷基体中包覆相的厚度适中,脱氮倾向不严重,基体的孔隙率较小;AlN的加入造成的晶粒细化强化与Al元素加入粘结相的强化作用占绝对主导,表现出了最优的摩擦性能。

Ti(C,N) cermet possesses the properties of excellent wear resistance and high corrosion resistance,which has been widely used in cutting tools,moulds,sliding bearings and other wear-resistant parts.However,it is badly worn or even destroyed when serving as dry self-mated wear pairs in sliding bearings.In order to enhance the properties of excellent wear resistance and high corrosion resistance further,Ti(C,N)-based cermets with different additions of AlN were prepared by powder metallurgy method.The mechanical properties of TRS,HRA,relative density,wear properties.etc were tested.Microstructure of the species with different additions of AlN were investigated by optical scope,SEM,EDS.The results showed that the typical core-rim structure of cermets could be found when AlN was added,and with the increase of AlN,the inner rim became blurry,outer rim became thinner,the average grain size decreased,the porosity increased.In the range of 0 and 1.0%,with the increase of AlN,the relative density of Ti(C,N)-based cermets decreased,HRA and TRS increased slightly.The self-mated dry friction properties increased first and then decreased,and the best properties were achieved when the addition of AlN was 0.5%.The addition of AlN caused the effect of grain refinement strengthening.The Al solid solved in binder phase strengthened the binder phase.However,the cermets tended to lose N because of the addition of AlN,and the porosity increased,the relative density decreased.When the addition content was 0.5%,the rim phase in the cermets showed the proper thickness,the tendency of losing N was not serious,the porosity was small,the effect of grain refinement strengthening and the Al solid solved in binder phase strengthening the binder phase were dominant.The cermets showed the best friction properties.