Preparation Of ZTAp/High Chromium Cast Iron Wear-resistant Composite Material By Dip Casting Method And Analysis Of Interface Structure

With the continuous development of wear-resistant parts in metallurgy,mining,power and other industries,traditional,single wear-resistant materials can no longer meet the application of production,ceramic/metal composite wear-resistant materials came into being,ZTAp/high-chromium cast iron wear-resistant composite materials are one of them.The main problems in the research of ZTAp/high-chromium cast iron composites are:the wetting between ceramics and metals is very poor,making it difficult to infiltrate and combine the two;and under high temperature conditions,the interface reaction,element diffusion,partial polymerization,solid solution,phase change,etc.occur at the interface between the high-chromium cast iron matrix and the ZTA ceramic reinforced phase,and the stability and reliability of ZTAp/high-chromium cast iron wear-resistant composite material products need to be improved.High-chromium cast iron is used as the matrix,and ZTAp（Zirconia-toughened alumina）ceramics are used as the reinforcing phase.ZTAp/high chromium cast iron wear-resistant composite material was prepared by die casting method.The microstructure and element distribution of the prepared composites were analyzed and discussed by SEM,EDS,XRD and other experimental methods,and the infiltration mechanism and interface bonding mechanism in the preparation of the composites were explored.Aiming at the hammer head of coal gangue pulverizer,the prefabricated structure of ceramic particles was designed,and the ceramic composite hammer head was successfully prepared by the above preparation process,and the preliminary application results were obtained.The following conclusions are drawn:（1）Mix the chemically plated ZTAp particles with water glass binder and active micropowder in a mass ratio of 10:2:2 to obtain a preform,and heat the ceramic preform at 350℃ for 20min.process,the compressive strength of the preform is 16 MPa and the porosity is close to 50%,which meets the standard for preform preparation.（2）There is a transition layer at the interface of the ZTAp/high chromium cast iron composite prepared by coating Ni-coated Cr and other active micropowders;Cr are mainly distributed in cast iron matrix;new phases such as Cr₂O₃,FeCr₂O₄,Al Ni and so on are detected.（3）The interface of ZTAp/high chromium cast iron composites prepared by coating Ni-coated Co and other active micropowders has an interface transition layer based on water glass;Co element is mainly distributed in the iron matrix.（4）The interface of ZTAp/high-chromium cast iron composites prepared by plated Ni-coated ZTA and other active micropowders has a water glass transition layer mainly composed of Si,Na,O,Al and other elements.The composition concentration distribution;Na Al O₂,Al Ni,3Al₂O₃.2SiO₂ and other new phases were detected;according to the literature,the compound formed by the interface water glass and alumina can improve the strength of the interface.（5）The interface of ZTAp/high chromium cast iron composites prepared by plated Ni-coated TiC and other active micropowders forms a transition layer dominated by TiC and Si/Na water glass,and has a good phase with iron-based and ceramic-based composites.（6）There is a transition layer at the interface of ZTAp/high chromium cast iron composite material prepared by coating Co-coated Cr and other active micropowders,and the elements in the transition layer are mainly Si,O,Al,Zr,etc.;Cr element is mainly distributed in the iron matrix;Co is distributed on both sides of the matrix;Al Co,3Al₂O₃·2SiO₂ and other phases were detected.（7）There is a transition layer at the interface of the ZTAp/high chromium cast iron composite material prepared by coating Co-coated ZTA and other active micropowders.The transition layer is based on sodium silicate and contains main diffusion elements such as Al,Zr,Cr,C,Fe,etc.;The distribution of ZTA active particles was detected at the site;phases such as NaAlSiO₄,3Al₂O₃·2SiO₂,and Co₃Fe₇ were detected.（8）There is a transition layer at the interface of the ZTAp/high chromium cast iron composite material prepared by plating Co and coating TiC and other active micropowders.The transition layer is based on sodium silicate,and there are diffusion distributions of Al,Zr,Cr,Fe,C and other elements.（9）Under the influence of element diffusion induced by Co,Ni,etc.and the affinity of TiC,ZTA,Cr and other active substances with the matrix,water glass is formed at the interface of ZTAp ceramics and high-chromium cast iron.As the base,Al,Zr ceramic elements and C,Fe,Cr matrix elements diffuse into the transition layer respectively.Al and Cr in the transition layer have stronger diffusivity than Zr and Fe,respectively.thereby promoting the infiltration of molten iron and ceramics,which is conducive to the formation of a tight interface between ceramics and high-chromium cast iron.combine.