The microstructural features and the consequent mechanical properties were characterized in aluminium borate whisker(ABOw)(5, 10 and 15 wt.%) reinforced commercially-pure aluminium composites fabricated by conventiona...The microstructural features and the consequent mechanical properties were characterized in aluminium borate whisker(ABOw)(5, 10 and 15 wt.%) reinforced commercially-pure aluminium composites fabricated by conventional powder metallurgy technique. The aluminium powder and the whisker were effectively blended by a semi-powder metallurgy method. The blended powder mixtures were cold compacted and sintered at 600 ℃. The sintered composites were characterized for microstructural features by optical microscopy(OM), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), transmission electron microscopy(TEM) and X-ray diffraction(XRD) analysis. Porosity in the composites with variation in ABOw contents was determined. The effect of variation in content of ABOw on mechanical properties, viz. hardness, bending strength and compressive strength of the composites was evaluated. The dry sliding wear behaviour was evaluated at varying sliding distance at constant loads. Maximum flexural strength of 172 MPa and compressive strength of 324 MPa with improved hardness around HV 40.2 are obtained in composite with 10 wt.% ABOw. Further increase in ABOw content deteriorates the properties. A substantial increase in wear resistance is also observed with 10 wt.% ABOw. The excellent combination of mechanical properties of Al-10 wt.%ABOw composites is attributed to good interfacial bonds, less porosity and uniformity in the microstructure.展开更多
CaSO 4 whisker reinforcing and toughening mechanisms for polyurethane elastomer were studied. The effects of dispersity of CaSO 4 whisker and interfacial bonding state on reinforcement and toughness were discussed.T...CaSO 4 whisker reinforcing and toughening mechanisms for polyurethane elastomer were studied. The effects of dispersity of CaSO 4 whisker and interfacial bonding state on reinforcement and toughness were discussed.The microanalyses showed that CaSO 4 whisker reinforcing mechanism for polyurethane elastomer mainly was load transferring and its toughening mechanism involved crack deflection and whisker pullout.The results indicated that composites with 5%-10% CaSO 4 whisker exhibited the best mechanical properties. Good bonding interface was formed between whisker and matrix after the surface of CaSO 4 whisker was treated by silane coupling agent.The fairly improved strength and toughness are attributed to the better interfacial bonding state.展开更多
The CaSO 4 whisker/polyurethane elastomer composites with high strength and high toughness are fabricated.The CaSO 4 whisker reinforcing and toughening mechanisms for polyurethane elastomer are studied.The observation...The CaSO 4 whisker/polyurethane elastomer composites with high strength and high toughness are fabricated.The CaSO 4 whisker reinforcing and toughening mechanisms for polyurethane elastomer are studied.The observation of the fracture surface by SEM and TEM shows that CaSO 4 whisker reinforcing mechanism for polyurethane elastomer is mainly load transfering,while its toughening mechanism involves crack deflection and whisker pullout.The effects of dispersity of CaSO 4 whisker and the interfacial bonding state on reinforcement and toughness are discussed.The results indicate that composites with 5%～10% CaSO 4 whisker exhibit the best mechanical properties among the materials tested.Good bonding interface is formed between whisker and matrix after the surface of CaSO 4 whisker being treated by silane coupling agent(KH 550).Better interfacial bonding state contributes to strength and toughness being fairly improved.展开更多
基金support provided by the Central Instrument Facility Centre(CIFC)of IIT(BHU)the Department of Ceramic Engineering especially Advance Refractory Lab(ARL)of IIT(BHU)Varanasi。
文摘The microstructural features and the consequent mechanical properties were characterized in aluminium borate whisker(ABOw)(5, 10 and 15 wt.%) reinforced commercially-pure aluminium composites fabricated by conventional powder metallurgy technique. The aluminium powder and the whisker were effectively blended by a semi-powder metallurgy method. The blended powder mixtures were cold compacted and sintered at 600 ℃. The sintered composites were characterized for microstructural features by optical microscopy(OM), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), transmission electron microscopy(TEM) and X-ray diffraction(XRD) analysis. Porosity in the composites with variation in ABOw contents was determined. The effect of variation in content of ABOw on mechanical properties, viz. hardness, bending strength and compressive strength of the composites was evaluated. The dry sliding wear behaviour was evaluated at varying sliding distance at constant loads. Maximum flexural strength of 172 MPa and compressive strength of 324 MPa with improved hardness around HV 40.2 are obtained in composite with 10 wt.% ABOw. Further increase in ABOw content deteriorates the properties. A substantial increase in wear resistance is also observed with 10 wt.% ABOw. The excellent combination of mechanical properties of Al-10 wt.%ABOw composites is attributed to good interfacial bonds, less porosity and uniformity in the microstructure.
基金FundedbytheNaturalScienceFoundationofShanxiProvince (No .9910 2 4 )
文摘CaSO 4 whisker reinforcing and toughening mechanisms for polyurethane elastomer were studied. The effects of dispersity of CaSO 4 whisker and interfacial bonding state on reinforcement and toughness were discussed.The microanalyses showed that CaSO 4 whisker reinforcing mechanism for polyurethane elastomer mainly was load transferring and its toughening mechanism involved crack deflection and whisker pullout.The results indicated that composites with 5%-10% CaSO 4 whisker exhibited the best mechanical properties. Good bonding interface was formed between whisker and matrix after the surface of CaSO 4 whisker was treated by silane coupling agent.The fairly improved strength and toughness are attributed to the better interfacial bonding state.
文摘The CaSO 4 whisker/polyurethane elastomer composites with high strength and high toughness are fabricated.The CaSO 4 whisker reinforcing and toughening mechanisms for polyurethane elastomer are studied.The observation of the fracture surface by SEM and TEM shows that CaSO 4 whisker reinforcing mechanism for polyurethane elastomer is mainly load transfering,while its toughening mechanism involves crack deflection and whisker pullout.The effects of dispersity of CaSO 4 whisker and the interfacial bonding state on reinforcement and toughness are discussed.The results indicate that composites with 5%～10% CaSO 4 whisker exhibit the best mechanical properties among the materials tested.Good bonding interface is formed between whisker and matrix after the surface of CaSO 4 whisker being treated by silane coupling agent(KH 550).Better interfacial bonding state contributes to strength and toughness being fairly improved.
