摘要
采用真空无压烧结法,制备了多孔碳化硼(B4C)骨架,致密度为46.8%。然后采用真空无压浸渗法,以A356铝合金为渗体,与B4C骨架进行复合。制备了B4C/Al-Si复合材料,致密度达99%以上,抗压强度为453MPa,弯曲强度为294MPa。微观结构分析结果表明,制备的复合材料组织致密,形成的Al、Si、Al3BC相分布均匀,界面复合良好。Al主要分布在B4C颗粒间,Si相主要分布在B4C和Al的界面处,使B4C和Al紧密结合,且试样的表面和心部均有分布均匀的Al存在。制备的B4C/Al-Si复合材料中B4C形成连续的骨架结构,而孔隙处的金属相则起到增韧、增强的作用。
Connected ceramic preforms (B4C) with porosity of 46.8% were fabricated by pressureless sintering in vacuum, then B4C/Al-Si composites with high ceramic fraction were prepared by pressureless infiltrating aluminum alloy A356 into the boron carbide preforms B4C, whose relative density, compressive strength and flexure strength are more than 99%, 453MPa and 294MPa, respectively. Microstructural observation reveals that prepared composites exhibit compact structure and desirable interface bonding, in which formed Al, Si and Al3BC phases are uniformly distributed. Al phase is mainly distributed in the cavity of B4C frames and Si mainly existed in the interface of B4C and Al phase, which results in the tough combination of B4C and Al phases, meanwhile, uniformly distributed Al phase can be observed in surface and inner of composite samples. B4C ceramics is formed continuous frame in the fabricated B4C/Al-Si composites and metallic phase existed in the cavity plays the role in toughening and strengthening effects.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2010年第4期367-369,共3页
Special Casting & Nonferrous Alloys
基金
东南大学人才引进科研启动项目(4012001110)
