Research Of Boride Abrasive-Resistant Composite Material On Cast-Iron

In order to improve the abrasion-resistant on the casting surface, this paper has studied surface alloy-reinforced composites. Abrasion-resistant powder composed of Fe-B and high-carbon ferrochrom after mixed with organic binder (PVA) at the time of pouring. The process of cast-infiltration was optimized by retangular method. No biowholes and siag inclusions defects compact metallurgically-combineded cast-infiltration layer was obtained on differentmatrix (iron ductile iron and steel), the thickness is 2~5mm, and the process parameter was decided. The as cast microstructure and distribution iaw of main elements and hardness in surface-alloyed zones were studied too. Furthermore,the combining intensity and wear-resistant property of cast-infiltration iayer was studied. The results show that, Fe2B -, (Cr,Fe)7C 3^ a-Fe and y-Fe are the main phases in cast-infiltration layer. Fe2B and (Cr,Fe)7C3 maintain intimate contact,formembracing structure. The distribution of main elements and hardness were uneven and have a certain law.The abrasive wear resistance is 5-9 times higher than HT200, 3~6 times higher than ductile iron,3-5 times higher than 45 quenched steel.An thermodynamic analysis was applied on the cast-infiltration mechanism and the application of Si-Ca alloy in the process of cast-infiltration. And dynamic analysis was applied on the process of the cast-infiltration. The interface question of composites was researched. We considered that the removal of the oxygenization velamen on the powder surface depended on deoxidization of the Si-Ca alloy , under the NaF's function of solubilization and absorbing, and then remove slag inclusions. We also considered that the reinforced body and matrix could wetalize and compound,consitute optimal interface-bonding.