Study On Preparation And Properties Of TiC/Fe Cermet And Its Graded Composites

Starting from the actual demand of high temperature,high speed and abrasion resistance,based on iron materials which are most widely used in industry as matrix,TiC hard particles as reinforcing phase,the experiment prepared uniform homogeneous TiC/Fe cermet.In order to effectively ease heat matching problems between homogeneous composite materials and traditional steel,experiment preparedgraded TiC/Fe composite materials as well.The graded TiC/Fe composite materials have great interfacial bonding and abrasion resistance property,so there is wide application prospect.Experiment prepared the TiC/Fe cermet and graded composite materials by pressureless sintering method.The experimental results show the best preparation process when the mass fraction of added zinc stearate is 0.5%,pressing pressure is 100MPa and sintering temperature is 1480 ℃,and the composite materials uniform and compact in appearance.The TiC volume fraction of the TiC/Fe cermet was 30%,40%,50%and 60%,respectively.When the TiC volume fraction of the sample of homogeneous TiC/Fe composite material is 50%,relative density reaches the maximum value of 99.1%,the flexural strength reached the maximum value of 1048MPa,the compression strength reaches the maximum value of 1689MPa;when the TiC volume fraction of the sample of the homogeneous TiC/Fe composite is 60%,hardness reaches the maximum value of 6200MPa.The interfacial bonding strength is measured by the method of measuring the compressive shearing strength to characterize the interfacial bonding properties of graded TiC/Fe composites.The experimental results show that the smaller the difference of the composition of the composite material on the graded layer,the lower the difference of the thermal expansion coefficient,the higher the interfacial bonding strength of the graded TiC/Fe composites.When the volume fraction of TiC on both sides of the graded TiC/Fe composite are 50%and 60%,and the size of the interface was 1mm*8mm,the compressive shearing strength of the graded TiC/Fe composite reaches the maximum value of 233MPa.The relationship between friction coefficient,wear rate and composition,apply loads and friction velocity of TiC/Fe cermet was studied.The experimental results show that when the apply load or friction velocity enhances individually,the friction process would produce more heat which reduced the friction coefficient of cermet;enhancing the volume fraction of TiC,cermet would contain more hard particles,thereby increasing the friction coefficient of the cermet under dry friction condition.The wear rate of cermet would decrease when the apply load or friction velocity enhances individually,but the wear rate increases with the increasing of friction velocity.The friction coefficient range of TiC/Fe cermet is 0.41-0.55,the wear rate range is 1.39×10-9-3.09×10-9mm3·N-1·m-1.The variation of friction coefficient and wear rate of TiC/Fe cermet is kept in a relatively small range,which proved that the TiC/Fe cermet have excellent wear resistance.