Study On Preparation And Wear Resistance Of Honeycomb Ceramic/Nodular Cast Iron Composite

The three-dimensional network ceramic/iron-based composite has the excellent properties of both ceramic and iron matrix,that is,the high hardness and wear resistance of ceramic,as well as the good strength and toughness of iron matrix,so it has been widely concerned.Compared with the traditional wear-resistant materials,the composite has higher comprehensive properties and can adapt to more complex conditions.At the same time,three-dimensional network ceramic/iron-based composite materials need to be further developed to achieve mass production applications.As one of the three-dimensional network ceramics,honeycomb ceramics is an excellent ceramic reinforcement because of its transparent pores and uniform distribution and high proportion of surface ceramics after composite with metal matrix;ductile iron has good strength and toughness and low production cost.Therefore,in this study,ductile iron was chosen as the matrix of composite,and honeycomb ceramics with different pore diameters were used as reinforcement.RSiC/nodular cast iron composite with 3 mm honeycomb diameter and Al₂O₃/nodular cast iron composite with 1 mm,2 mm and 3 mm honeycomb diameter were successfully prepared by EPC process.The nodular cast iron without honeycomb ceramic was used as the contrast sample.The microstructure and properties of the composite were studied by SEM,laser confocal microscope,Vickers hardness tester and end friction and wear tester.The results show that:RSiC/nodular cast iron sample and Al₂O₃/nodular cast iron sample are in good composite condition.There is no obvious defect in the joint position of ceramic and nodular cast iron.In the RSiC/nodular cast iron sample,the main bonding mode between RSiC ceramics and nodular cast iron matrix is mechanical bonding,and a small amount of interface reaction occurs at the interface to form brittle phase.The distribution of C and Ni elements on the interface is concentrated on the matrix side of the interface,and gradually decreases along the matrix direction.The interface of Al₂O₃/nodular cast iron is mechanical,but there is no interface reaction,and there are fine Al2O3 particles at the interface with micro graphite aggregation.Compared with nodular cast iron,the matrix structure in the honeycomb of composite sample is more and more homogeneous.The content of ferrite decreased,the content of pearlite increased,the distance between pearlite lamellae increased,and the growth direction was more orderly.Under the same friction and wear test conditions of normal load of 100 N,rotating speed of 100 R/min and time of 10 min,the average weight loss of nodular cast iron sample is 0.5659g,the average weight loss of RSiC/nodular cast iron with 3mm honeycomb diameter is 0.2047g,the average weight loss of Al2O3/nodular cast iron with 3 mm honeycomb diameter is0.1344 g.The wear resistance of nodular cast iron sample is the worst,and Al2O3/nodular cast iron sample is the best.Under the same experimental conditions,the wear resistance of Al2O3/nodular cast iron with a honeycomb diameter of 2 mm is better than that of Al2O3/nodular cast iron with a honeycomb diameter of 3 mm.The best reinforcement of the composite is Al2O3honeycomb ceramic with a honeycomb diameter of 2 mm.The main wear mechanisms of RSiC/nodular cast iron and Al2O3/nodular cast iron are abrasive wear,adhesive wear and oxidation wear.