Study On Densification Technology Of Mo₂FeB₂ Cermet

Mo₂FeB₂ cermet has high hardness,wear resistance,corrosion resistance,high temperature performance characteristics and resistance to fatigue,and good metallurgical bonding with steel,lower costs of raw materials,wide application prospect in new hard materials.Currently,Mo₂FeB₂ cermet materials that be used in industrial production has low flexural strength and great brittleness and other issues,this hinder the further application of materials.The direct cause of the problem is the poor compactness of the materials.Therefore,to improve the compactness of the material is essential.This paper has researched the influence of preparation process,alloying elements,sintering methods and subsequent processing on cermet densification.Firstly,the effect of ball milling time and heating rate on Mo₂FeB₂ cermet densification in preparation process have been researched.The results showed that:the proper extension of ball milling time can reduce the porosity of the material,refine the organization to significantly improve the mechanical properties,when the milling time is 30 h,the Mo₂FeB₂ cermet has the best compactness,optimal mechanical performance;During the sintering process the rate of temperature rise too quickly can cause the specimen deformation,and internal porosity increased.The heating rate is too slow will lead to coarsening of organization,With self-designed composite heating rate,Mo₂FeB₂ cermet is dense,and its mechanical performance is excellent,and its porosity is 0.8%,hardness is HRA83.4,bending strength is1612.1MPa.Secondly,the the effect of alloying elements Cu on compactness of Mo₂FeB₂ cermet has been researched.The results showed that: Cu element can significantly improve material density,and can refine and ball hard phase particles,,Mo₂FeB₂ cermet has best performance with adding 4% Cu element,its porosity is 0.54%,the hardness is HRA86.0,and its strength has increased 1529.4MPa.Thirdly,the effect of hot pressed sintering on compactness of Mo₂FeB₂ cermet has been researched.The results showed that: hot pressing sintering significantlyimproved density of Mo₂FeB₂ cermet,compared with the vacuum sintering,the porosity decreased from 0.54% to 0.3%,the hardness and bending strength has been increased by 2.2% and 15%.Finally,the effect of post heat treatment on compactness of Mo₂FeB₂ cermet has been researched.The results showed that: As treatment temperature increased,material is more dense,the organization is more fine,and its mechanical properties is better,when the heat treatment temperature is 1100 ?,the material can achieve the best overall performance,and its porosity is 0.15%,hardness is HRA90.5,bending strength is 2160.0MPa.