Study On Preparation Of Low Cost Boron Carbide Ceramic Composite By Glass Infiltration

The preparation of boron carbide ceramic composites by melt infiltration method has many advantages,such as low preparation temperature,short preparation time,simple preparation process,low cost,no shrinkage of the product before and after infiltration.So this preparation method has aroused people’s interest.As for preparation of boron carbide ceramic composite by melt infiltration,researchers mainly focus on aluminum alloy infiltration and silicon infiltration currently.The preparation of boron carbide ceramic materials by glass infiltration has not been reported.High boron content glass frit 620-1 and glass frit 2011 were used as infiltrants in this paper.The wettability of glss frit to boron carbide,infiltration temperature and micro structure,densification and mechanical properties of glass-boron carbide composite were studied.Furthermore,the effects of TiB2 content on the micro structure,densification and mechanical properties of glass infiltrated boron carbide composites were studied.Finally,boron carbide ceramic composites with excellent properties were prepared.The research results of this paper have important theoretical significance and application value for the further application and popularization of low-cost boron carbide ceramic materials fabricated by glass melt infiltration.Firstly,the preparation process,microstructure and mechanical properties of B4C-glass composites prepared by vacuum infiltration of high-boron content glass frit 620-1 were studied.The results show:The optimal infiltration temperature of glass-boron carbide composite which is vacuum infiltrated by high boron content glass frit 620-1 is 1550℃.The density,relative density,apparent porosity,flexural strength,fracture toughness and Vickers hardness of glass-boron carbide composite were 2.50 g/cm3,98.1%,0.13%,252 MPa,3.96 MPa·m1/2 and 13.0 GPa,respectively.Then,the preparation process,microstructure and mechanical properties of B4C-glass composites prepared by vacuum infiltration of glass frit 2011 were studied.The results show:The glass-boron carbide composite infiltrated by glass frit 2011 has better mechanical properties.The optimal infiltration temperature of glass-boron carbide composite which is vacuum infiltrated by glass frit 2011 is 1450℃.The density,relative density,apparent porosity,flexural strength,fracture toughness and Vickers hardness of glass-boron carbide composite were 2.64 g/cm3,99.2%,0.38%,271 MPa,4.35 MPa·m1/2 and 14.8 GPa,respectively.Finally,the effect of TiB2 content of the B4C-TiB2 composite infiltrated by frit 2011 on micro structure and mechanical properties of the composites were studied.The results show:B4C-TiB2 composite infiltrated by glass frit 2011 has better mechanical properties than glass-boron carbide composite.The optimal mass fraction of TiB2 added to the boron carbide green body is 5 wt%.The density,relative density,apparent porosity,flexural strength,fracture toughness and Vickers hardness of B4C-TiB2 carbide-composite were 2.67 g/cm3,99.3%,0.07%,285 MPa,4.42 MPa·m1/2 and 15.1 GPa,respectively.