Design And Fabrication Of Wear Resistant Metal Matrix Composites Mounted With Ceramic By Cast

Ceramic/metal wear-resistant composites play an important role in the field of wear resistant materials.It can not only retain good plasticity and toughness of metal materials,but also have a series of advantages,such as high temperature resistance,high strength,high hardness and low density of ceramics.Therefore,it becomes the first choice to replace the traditional single wear-resistant material.With the progress of analytical methods,reduction of manufacturing cost and the continuous maturing of the preparation process,ceramic/metal wear-resistant composites will play a greater role in many fields,such as machinery,metallurgy,mining and so on.In this paper,a series of designs and experiments were carried out on the interface bonding of composite materials,the volume fraction control and distribution of ceramics,the wear resistance and the processing of composite materials preparation.Firstly,the metal coating was deposited on the surface of Al2O3 ceramic by chemical vapor deposition,and the interface control between Al2O3 ceramic and high chromium cast iron was preliminarily realized.On the basis of this,wear-resistant layers of composite materials with different structures were prepared.It provides a new idea for the design and preparation of composite materials in the future.The experimental results show that:(1)Ti coating is deposited on the surface of Al2O3 ceramic by chemical vapor deposition.The thickness of Ti coating can be well controlled by controlling the amount of reactants and holding time.(2)Adequate reaction can be achieved between Ti,high chromium cast iron and Al2O3 by controlling the thickness of Ti(about 5 ?m).At the interface of composite materials there are new phases formation such as FeAlTiO5,Fe Ti2.603O0.35,Fe2 Ti and TiC,which give a good combination at the interface of the composite.(3)When the thickness of Ti coating deposited by chemical vapor deposition is large,there is obvious stratification in the composite interface,which can be divided into three layers,the size of each layer region associated with the diffusion of atoms and a variety of physical and chemical reactions.(4)The composites with different arrangement and shapes of Al2O3 ceramics(cubic,cylindrical)have improved the wear resistance of the materials in different degrees.(5)The composites prepared by depositing Ti coating show better wear resistance than those deposited with Ni,Cu and no coating.(6)The edges and corners of the cubic Al2O3 ceramic often cause defects in the composites,which aggravate the friction and wear of the materials in the process of wear.Therefore the wear resistance is worse than the composites reinforced by cylindrical Al2O3 ceramic.(7)Three-dimensional network Al2O3 ceramic with controllable structure and size can be successfully prepared by using polystyrene foam.(8)The three-dimensional network Al2O3 ceramic coated with Ti and Ni coating is beneficial to the penetration of molten metal,and the ceramic preform coated with Ti is firmly bonded with the metal matrix,thereby improving the machinability of the material.