(合肥工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，合肥 230009)
摘 要: 采用高壓扭轉(zhuǎn)工藝將SiC和Al的混合粉末直接制備金屬基復(fù)合材料。用金相顯微鏡、顯微維氏硬度計(jì)、萬(wàn)能試驗(yàn)機(jī)和掃描電鏡分析壓力對(duì)SiCp-Al復(fù)合材料的顯微組織和力學(xué)性能的影響。結(jié)果表明：壓力越高，對(duì)SiCp-Al復(fù)合材料粉末成形的應(yīng)變積累越有利；壓力越高，扭轉(zhuǎn)前粉末的致密程度越高，對(duì)SiCp-Al復(fù)合材料粉末成形的應(yīng)變積累越有利，SiC顆粒在Al基體內(nèi)的分布越均勻，顯微硬度有所提高，但增幅不大；當(dāng)壓力從0.5 GPa增大至0.62 GPa，材料的屈服強(qiáng)度增加32.6%，但抗拉強(qiáng)度和伸長(zhǎng)率均分別減小4%和25.5%。拉伸斷口以大小不一的脫粘韌窩為主要特征。
關(guān)鍵字: SiCp-Al復(fù)合材料；高壓扭轉(zhuǎn)；顯微組織；力學(xué)性能
（School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China）
Abstract:SiC particles and Al powder mixtures (SiCp-Al composites) were successfully fabricated into the metal matrix composites by high-pressure torsion (HPT). The effects of pressure on the microstructure and mechanical properties of the composites were investigated by optical telescope, microhardness-testing device, universal testing machine and scanning electronic telescope. The results show that higher pressure is more helpful to the strain accumulation during the power forming of SiCp-Al composites. In the HPT process, the higher the pressure is, the better the powerful densification is, the higher the accumulated strain is, and the more homogeneous of the SiC particles are, while the increase of microhardness is not so high. When the pressure increases from 0.5 GPa to 0.62 GPa, the yield strength increases by 32.6%, while the tensile strength and elongation decrease by 4% and 25.5%, respectively. The fracture surface of the dimples shows various sizes as the main feature.
Key words: SiCp-Al composites; high-pressure torsion; microstructure; mechanical property
