SiC_w Al and SiC_p/Al composites have been produced by an uhrasonic vibration casting technique. Ultrasound irradiation promoted the wetting of reinforcements in aluminum liquid, improved the reinforcement distributio...SiC_w Al and SiC_p/Al composites have been produced by an uhrasonic vibration casting technique. Ultrasound irradiation promoted the wetting of reinforcements in aluminum liquid, improved the reinforcement distribution in the metal matrix, and reduced porosity. The composites can be remelted. Initial studies of the preparation procedures, microstructure, fracture surface morphology and remelting properties of SiC_w/Al and SiC_p/Al composites fabricated by ultrasonic vibration liquid are presented in this work.展开更多
SiCw/Al-18Si composites were prepared by squeeze casting technique.Solidification behavior of SiCw/Al-18Si composites was studied by differential scanning calorimeter(DSC) and scanning electron microscopy(SEM).The re-...SiCw/Al-18Si composites were prepared by squeeze casting technique.Solidification behavior of SiCw/Al-18Si composites was studied by differential scanning calorimeter(DSC) and scanning electron microscopy(SEM).The re-melting temperature has little effect on the solidification behavior and microstructure of composites.With the increase of SiC whisker content,onset and peak temperatures of primary Si decrease and the average size of primary silicon becomes smaller and smaller.Sr addition lowers onset and peak temperatures of primary Si,however,onset and peak temperatures of eutectic were barely affected by Sr addition.The average sizes of primary Si and Al-Si eutectic both decrease by Sr addition.展开更多
The rules such as process parameters affecting joint properties and theevolution principle of weld's microstructure have been researched by adopting diffusion weldingprocess to connect SiC_w/6061Al composite. Expe...The rules such as process parameters affecting joint properties and theevolution principle of weld's microstructure have been researched by adopting diffusion weldingprocess to connect SiC_w/6061Al composite. Experimental results show that there exists a criticaltemperature region between solid and liquid phase line of SiC_w/6061Al composite, and the regionwill shrink with the increasing of welding pressure. When diffusion welding occurred under thecritical temperature region, welding joint exhibits bad property of bonding, and the matrix and thereinforcement can't bond effectively. When diffusion welding occurred in the critical temperatureregion, the strength of welding joint changes widely with the variation of welding temperature. Whenwelding temperature varies in 10 deg C, the strength of welding joint will change obviously. Onlywhen welding temperature is higher than the critical temperature region, stable joint properties canbe obtained. Simultaneously the matrix and the reinforcement has better interfacial bonded indiffusion welding interface, and no obvious interface reaction occurred, and thus diffusion weldingof SiC_w/6061 Al composite can be successfully realized.展开更多
用粉末冶金真空热压工艺制备了碳化硅晶须(SiC_w)及碳化硅颗粒(SiC_p)增强 Al 合金加纯 Al 复合基体新型复合材料。研究了加工工艺、增强相的数量、尺寸、类型及基体成分对复合材料塑性的影响。15v .-%SiCp 增强2024A+Al复合材料的延伸...用粉末冶金真空热压工艺制备了碳化硅晶须(SiC_w)及碳化硅颗粒(SiC_p)增强 Al 合金加纯 Al 复合基体新型复合材料。研究了加工工艺、增强相的数量、尺寸、类型及基体成分对复合材料塑性的影响。15v .-%SiCp 增强2024A+Al复合材料的延伸率达到9.0%。展开更多
文摘SiC_w Al and SiC_p/Al composites have been produced by an uhrasonic vibration casting technique. Ultrasound irradiation promoted the wetting of reinforcements in aluminum liquid, improved the reinforcement distribution in the metal matrix, and reduced porosity. The composites can be remelted. Initial studies of the preparation procedures, microstructure, fracture surface morphology and remelting properties of SiC_w/Al and SiC_p/Al composites fabricated by ultrasonic vibration liquid are presented in this work.
文摘SiCw/Al-18Si composites were prepared by squeeze casting technique.Solidification behavior of SiCw/Al-18Si composites was studied by differential scanning calorimeter(DSC) and scanning electron microscopy(SEM).The re-melting temperature has little effect on the solidification behavior and microstructure of composites.With the increase of SiC whisker content,onset and peak temperatures of primary Si decrease and the average size of primary silicon becomes smaller and smaller.Sr addition lowers onset and peak temperatures of primary Si,however,onset and peak temperatures of eutectic were barely affected by Sr addition.The average sizes of primary Si and Al-Si eutectic both decrease by Sr addition.
文摘The rules such as process parameters affecting joint properties and theevolution principle of weld's microstructure have been researched by adopting diffusion weldingprocess to connect SiC_w/6061Al composite. Experimental results show that there exists a criticaltemperature region between solid and liquid phase line of SiC_w/6061Al composite, and the regionwill shrink with the increasing of welding pressure. When diffusion welding occurred under thecritical temperature region, welding joint exhibits bad property of bonding, and the matrix and thereinforcement can't bond effectively. When diffusion welding occurred in the critical temperatureregion, the strength of welding joint changes widely with the variation of welding temperature. Whenwelding temperature varies in 10 deg C, the strength of welding joint will change obviously. Onlywhen welding temperature is higher than the critical temperature region, stable joint properties canbe obtained. Simultaneously the matrix and the reinforcement has better interfacial bonded indiffusion welding interface, and no obvious interface reaction occurred, and thus diffusion weldingof SiC_w/6061 Al composite can be successfully realized.
