【摘要】 针对Si C/Al复合材料搅拌摩擦加工工艺参数敏感的挑战，本研究以25%SiC（质量分数）+1.5%TiO₂（质量分数）+1%CNT/Al（体积分数）-1%Cu（质量分数）为原料制备的复合材料为对象，探究搅拌摩擦加工行进速度对微观组织与力学性能的影响规律，为制动盘工艺优化提供依据。采用粉末冶金工艺制备基体材料，通过单道次搅拌摩擦加工（行进速度分别为50和100 mm/min）得到FSP50、FSP100试样。通过微观组织分析及拉伸性能测试，系统研究了搅拌摩擦加工行进速度对复合材料微观组织、室温及300℃拉伸性能的影响。结果表明，FSP通过剪切-流变协同作用促进Si C颗粒均匀分布；通过热-力耦合作用细化Al₃Ti及Al₂Cu颗粒尺寸；晶粒尺寸随行进速度增加而细化；FSP100通过细晶强化和组织均匀化提升室温强度，抗拉强度达407 MPa;300℃下基体软化与界面退化导致复合材料强度下降；FSP引入的细小Si C颗粒界面在高温下更易发生脱粘。更多还原

【Abstract】 To address the challenge of determining the process parameter sensitivity in friction stir processing（FSP） of SiC/Al composites, this study investigated the influence of travel speed on the microstructure and mechanical properties of a 25 wt.% SiC+1.5 wt.% TiO₂+1 vol.% CNT/Al-1 wt.% Cu composite, aiming to provide a theoretical basis for optimizing the manufacturing process of brake discs. The base material was fabricated via powder metallurgy, and single-pass FSP was subsequently conducted using travel speeds of 50 mm/min（sample FSP50） and 100 mm/min（sample FSP100）. Through microstructural characterization and tensile testing, a systematic analysis was conducted to evaluate the influence of travel speed on the microstructure and tensile properties at both room temperature and 300 ℃. The results indicate that FSP promotes a homogeneous distribution of SiC particles through the combined effects of shear and rheological flow; the thermomechanical coupling during FSP effectively refines the Al₃Ti and Al₂Cu particles, and the grain size decreases with increasing FSP travel speed. FSP100 exhibits an enhancement in room-temperature tensile strength, reaching 407 MPa,which is attributed to increased grain boundary strengthening and improved microstructural homogeneity; at 300 ℃, the composite strength decreases due to matrix softening and interfacial degradation. The fine SiC particle-Al interfaces introduced by FSP are more susceptible to debonding under high-temperature conditions.更多还原