Study On The Three-body Abrasive Wear Performance Of The Space Structure Toughened ZTAp/steel Composite Material

Conventional ceramic particle reinforced metal matrix composites(MMCs)uniformly disperse the particles in the metal matrix,which can improve the strength and wear resistance of the material to some extent,but can not maximize the synergistic effect of each component.The MMCs are divided into enhanced particle enrichment regions(composite regions)and pure matrix continuous regions with uniform spatial distribution,and the spatial structure toughening is a new way to improve the wear performance of composites.In this paper,Zirconia-toughened alumina(ZTA)ceramic particle reinforced 40 Cr steel matrix composites were prepared by extrusion casting method,and the volume fraction of the spatial structure of the composite zone was studied to be 35%,50%,and 65%.The material structure is tempered martensite(627.3HV),tempered troostite(326.5HV),pearlite + ferrite(235.7HV);The effect of the inter-facial bonding properties of ceramics and matrix(the addition of activated element Ti is 0%,10%,20%)on the triaxial abrasive wear properties of the spatially toughened ZTA/steel matrix composites.SEM,EDS,XRD and other methods were used to characterize the structural characteristics,element distribution,wear surface and subsurface morphology and microstructure of the structurally toughened ZTA ceramic/steel matrix composites.The wear model analyzes and discusses the wear mechanism of the composite.Concluded as follow:The effect of volume fraction of composite composite zone on the wear performance of three-body abrasive was studied.In the spatial composites,the triad abrasive wear performance of the composite with a volume fraction of 50% increased by 5.2% and 24.4% compared with the composites with a volume fraction of 35% and 65%,respectively.The wear resistance of the toughened ZTA ceramic/steel-based composite material is 34.4% higher than that of the conventional ceramic particle reinforced steel matrix composite.A mathematical model of composite wear was established.It is verified by the wear model that in the spatial composites,the columnar composite zone has a diameter of 4.0-4.5 mm,that is,the composite with a volume fraction of 50% has the best three-body abrasive wear performance.The effects of different matrix structures of composite materials on the triaxial abrasivewear properties were investigated.Compared with the tempered troostite and ferrite + pearlite structure,the three-body abrasive wear performance of the composite material was increased by2.1% and 18.2%,respectively.This is because the hardness of the tempered martensite is higher,which reduces the loss of the composite matrix during wear.The annealed ferrite + pearlite structure has a lower hardness and the matrix wear is more serious.The effect of interface activating elements on the triaxial abrasive wear properties of composites was investigated.Compared with the composite material without activation element,the composite material with the interface activation element Ti increased the wear resistance of the three-body abrasive by 12.8%.However,the wear resistance of the three-body abrasive was reduced by 10.7% compared with the composite material with Ti content of 20%.This is because Ti enhances the bonding strength between the ceramic and the substrate,and also promotes the formation of ferrite in the matrix,resulting in a decrease in the hardness of the matrix and a decrease in the wear properties of the composite.Therefore,the amount of Ti added must be limited.