A novel liquid settling method was investigated and applied to fabricate TC4 spherical particle reinforced AZ91 alloy matrix composites.This method was called liquid state settling technique in which TC4 particles wou...A novel liquid settling method was investigated and applied to fabricate TC4 spherical particle reinforced AZ91 alloy matrix composites.This method was called liquid state settling technique in which TC4 particles would settle down under the force of gravity.High volume fraction(50%)particle reinforced AZ91 composites could be easily obtained via this novel method.This is difficult to achieve for other traditional liquid fabrication methods.In addition,there was a good dispersion of TC4 particles in the AZ91 matrix and no clusters were found,which indicate that this method was feasible.Interfacial reaction occurred and the reaction product was confirmed to be Al2Ti.Three kinds of pre-dispersion technologies were used before the settling process and different interfacial microstructures were found.Theoretical calculation and experimental results both indicated that the interfacial product which was embedded in the matrix strengthened the composites and improved the tensile strength.展开更多
High-performance thermoplastic composites have been developed as significant structural materials for cutting-edge equipment in the aerospace and defence fields.However,the internal mechanism of processing parameters ...High-performance thermoplastic composites have been developed as significant structural materials for cutting-edge equipment in the aerospace and defence fields.However,the internal mechanism of processing parameters on mechanical properties in the manufacturing process of thermoplastic composite structures is still a serious challenge.The purpose of this study is to investigate the process/crystallization/property relationships for continuous carbon fiber(CF)reinforced polyether-ether-ketone(PEEK)composites.The composite laminates are fabricated according to orthogonal experiments via the thermoforming method.The mechanical performance is investigated in terms of crystallization properties and fracture morphology characterizations.Experimental results show that the mechanical performance and crystallization properties of thermoplastic composites are significantly affected by the coupling of processing parameters.The increased molding temperature,pressure,and holding time improve the degree of fiber/matrix infiltration and affect the crystallinity and crystalline morphology of the matrix,which further influences the mechanical properties of the composites.This is reflected in the test results that crystallinity has an approximately linear effect on mode-I interlaminar fracture toughness and transverse flexural modulus.As well as the higher molding temperature can destroy the pre-existent crystals to improve the toughness of the matrix,and the well-defined crystalline structures can be observed when fabricated at higher temperatures and longer periods of holding time.展开更多
Currently, many gratifying signs of progress have been made in magnesium(Mg) matrix composites(MMCs) by virtue of their high mechanical properties both at room and elevated temperatures. Although the commonly used rei...Currently, many gratifying signs of progress have been made in magnesium(Mg) matrix composites(MMCs) by virtue of their high mechanical properties both at room and elevated temperatures. Although the commonly used reinforcements in MMCs are ceramic particles,they often provide improved yield and ultimate stresses by a significant loss in ductility. Therefore, hard metallic phases were introduced as alternative candidates for the manufacturing of MMCs, especially titanium(Ti). It has a high melting point, high Young’s modulus, high plasticity, low level of mutual solubility with Mg matrix, and closer thermal expansion coefficient to that of Mg metal than that of ceramic particles. It is highly preferable to provide both high ultimate stress and ductility in Mg matrix. However, many critical challenges for the fabrication of Ti-reinforced MMCs remain, such as Ti’s homogeneity, low recovery rate, and the optimization of interfacial bonding strength between Mg and Ti, etc. Meanwhile, different fabrication methods have various effects on the microstructures, mechanical properties, and the interfacial strength of Ti-reinforced MMCs. Hence, this review placed emphasis on the microstructural characteristics and mechanical properties of Ti-reinforced MMCs fabricated by different techniques. The influencing factors that govern the strengthening mechanisms were systematically compared and discussed. Future research trends, key issues, and prospects were also proposed to develop Ti-reinforced MMCs.展开更多
Cu47Ti33Zr11Ni6Sn2Si1-based bulk metallic glass matrix composites reinforced with tungsten wires were fabricated by infiltration process at different temperatures （850, 900, 950 and 1000 °C） and time （10, 20 a...Cu47Ti33Zr11Ni6Sn2Si1-based bulk metallic glass matrix composites reinforced with tungsten wires were fabricated by infiltration process at different temperatures （850, 900, 950 and 1000 °C） and time （10, 20 and 30 min） in a quartz or a steel tube. The mechanical tests were carried out by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The results show that the maximum strength and total strain of the composite are 1778 MPa and 2.8% fabricated in steel tube at 900 °C for 10 min, and 1582 MPa and 3.6% fabricated in quartz tube at 850 °C for 10 min, respectively.展开更多
The hot-plate rolling(HPR)process is adopted to achieve the optimal strength-ductility for the in-situ nano-TiC_(P)/Al-Mg-Si composites.There was no crack in the sheet by single pass of hot-plate rolling with a thickn...The hot-plate rolling(HPR)process is adopted to achieve the optimal strength-ductility for the in-situ nano-TiC_(P)/Al-Mg-Si composites.There was no crack in the sheet by single pass of hot-plate rolling with a thickness reduction of 80%,while there were numerous cracks in the sheet by two passes of conventional hot rolling to achieve a total reduction of 50%.The microstructure and mechanical properties of the composites subjected to 80%thickness reduction of hot rolling at 540℃were investigated by tensile tests,scanning electron microscopy,and electron backscatter diffraction.The yield strength and ultimate tensile strength of in-situ nano-TiC_(P)/Al-Mg-Si composites after the hot-plate rolling process and T6 heat treatment increased significantly due to the dislocation strengthening and precipitation strengthening.展开更多
In the last two decades, light-weight magnesium matrix composites have been the hot issue of material field due to their excellent mechanical and physical properties, e.g., high-specific strength and modulus, good wea...In the last two decades, light-weight magnesium matrix composites have been the hot issue of material field due to their excellent mechanical and physical properties, e.g., high-specific strength and modulus, good wear resistance, and damping capacity. As compared with aluminum matrix composites, magnesium matrix composites have merit in their specific weight and have wide applications in aerospace and aeronautical fields. Generally, the processing techniques for magnesium matrix composites can be categorized as conventional and special processing routes. In recent years, as a special processing route, metal melt infiltration into porous ceramic preform featured by its low cost and availability of high-volume fraction of reinforced ceramics have been receiving much attention. Thus, in this review, one emphasis was put on the description of this processing technique in association with the means to obtain good wettability, the prerequisite for this kind of processing method. Based on the recognized fact that there exist clean interface and bonding ability between ceramics and matrix metal, in-situ reaction synthesis is usually utilized to fabricate magnesium matrix composites. Therefore, the interfacial feature was also reviewed for the in-situ reaction synthesis. Characterizations of microstructures and various mechanical-physical properties were finally summarized for magnesium matrix composites including tensile response, wear resistance, creep behavior, and damping capacity.展开更多
Carbon nanotube-reinforced 2009Al （CNT/2009Al） composites with randomly oriented CNTs and aligned CNTs were fabricated by friction stir processing （FSP） and FSP-rolling, respectively. The CNT/2009A1 composites wit...Carbon nanotube-reinforced 2009Al （CNT/2009Al） composites with randomly oriented CNTs and aligned CNTs were fabricated by friction stir processing （FSP） and FSP-rolling, respectively. The CNT/2009A1 composites with aligned CNTs showed much better tensile properties at room temperature and elevated temperature compared with those with the randomly oriented CNTs, which is mainly attributed to larger equivalent aspect ratio of the CNTs and avoidance of preferential fracture problems. However, much finer grain size was not beneficial to obtaining high strength above 473 K. The aligned CNTs resulted in tensile anisotropy, with the best tensile properties being achieved along the direction of CNT aligning. As the off-axis angle increased, the tensile properties were reduced due to the weakening of the load transfer ability. Furthermore, aligned CNTs resulted in much lower coefficient of thermal expansion compared with randomly oriented CNTs.展开更多
基金the National Natural Science Foundation of China(Grant No.51471059).
文摘A novel liquid settling method was investigated and applied to fabricate TC4 spherical particle reinforced AZ91 alloy matrix composites.This method was called liquid state settling technique in which TC4 particles would settle down under the force of gravity.High volume fraction(50%)particle reinforced AZ91 composites could be easily obtained via this novel method.This is difficult to achieve for other traditional liquid fabrication methods.In addition,there was a good dispersion of TC4 particles in the AZ91 matrix and no clusters were found,which indicate that this method was feasible.Interfacial reaction occurred and the reaction product was confirmed to be Al2Ti.Three kinds of pre-dispersion technologies were used before the settling process and different interfacial microstructures were found.Theoretical calculation and experimental results both indicated that the interfacial product which was embedded in the matrix strengthened the composites and improved the tensile strength.
基金financial support of the National Natural Science Foundation of China(NO.11902255,U1837601 and 52090051).
文摘High-performance thermoplastic composites have been developed as significant structural materials for cutting-edge equipment in the aerospace and defence fields.However,the internal mechanism of processing parameters on mechanical properties in the manufacturing process of thermoplastic composite structures is still a serious challenge.The purpose of this study is to investigate the process/crystallization/property relationships for continuous carbon fiber(CF)reinforced polyether-ether-ketone(PEEK)composites.The composite laminates are fabricated according to orthogonal experiments via the thermoforming method.The mechanical performance is investigated in terms of crystallization properties and fracture morphology characterizations.Experimental results show that the mechanical performance and crystallization properties of thermoplastic composites are significantly affected by the coupling of processing parameters.The increased molding temperature,pressure,and holding time improve the degree of fiber/matrix infiltration and affect the crystallinity and crystalline morphology of the matrix,which further influences the mechanical properties of the composites.This is reflected in the test results that crystallinity has an approximately linear effect on mode-I interlaminar fracture toughness and transverse flexural modulus.As well as the higher molding temperature can destroy the pre-existent crystals to improve the toughness of the matrix,and the well-defined crystalline structures can be observed when fabricated at higher temperatures and longer periods of holding time.
基金National Natural Science Foundation of China (52101123, 52171103)Guangdong Major Project of Basic and Applied Basic Research (2020B0301030006) for the support。
文摘Currently, many gratifying signs of progress have been made in magnesium(Mg) matrix composites(MMCs) by virtue of their high mechanical properties both at room and elevated temperatures. Although the commonly used reinforcements in MMCs are ceramic particles,they often provide improved yield and ultimate stresses by a significant loss in ductility. Therefore, hard metallic phases were introduced as alternative candidates for the manufacturing of MMCs, especially titanium(Ti). It has a high melting point, high Young’s modulus, high plasticity, low level of mutual solubility with Mg matrix, and closer thermal expansion coefficient to that of Mg metal than that of ceramic particles. It is highly preferable to provide both high ultimate stress and ductility in Mg matrix. However, many critical challenges for the fabrication of Ti-reinforced MMCs remain, such as Ti’s homogeneity, low recovery rate, and the optimization of interfacial bonding strength between Mg and Ti, etc. Meanwhile, different fabrication methods have various effects on the microstructures, mechanical properties, and the interfacial strength of Ti-reinforced MMCs. Hence, this review placed emphasis on the microstructural characteristics and mechanical properties of Ti-reinforced MMCs fabricated by different techniques. The influencing factors that govern the strengthening mechanisms were systematically compared and discussed. Future research trends, key issues, and prospects were also proposed to develop Ti-reinforced MMCs.
文摘Cu47Ti33Zr11Ni6Sn2Si1-based bulk metallic glass matrix composites reinforced with tungsten wires were fabricated by infiltration process at different temperatures （850, 900, 950 and 1000 °C） and time （10, 20 and 30 min） in a quartz or a steel tube. The mechanical tests were carried out by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The results show that the maximum strength and total strain of the composite are 1778 MPa and 2.8% fabricated in steel tube at 900 °C for 10 min, and 1582 MPa and 3.6% fabricated in quartz tube at 850 °C for 10 min, respectively.
基金the National Natural Science Foundation of China(No.51790483)。
文摘The hot-plate rolling(HPR)process is adopted to achieve the optimal strength-ductility for the in-situ nano-TiC_(P)/Al-Mg-Si composites.There was no crack in the sheet by single pass of hot-plate rolling with a thickness reduction of 80%,while there were numerous cracks in the sheet by two passes of conventional hot rolling to achieve a total reduction of 50%.The microstructure and mechanical properties of the composites subjected to 80%thickness reduction of hot rolling at 540℃were investigated by tensile tests,scanning electron microscopy,and electron backscatter diffraction.The yield strength and ultimate tensile strength of in-situ nano-TiC_(P)/Al-Mg-Si composites after the hot-plate rolling process and T6 heat treatment increased significantly due to the dislocation strengthening and precipitation strengthening.
基金financially supported by the National Natural Science Foundation of China (Grant No.51271051)
文摘In the last two decades, light-weight magnesium matrix composites have been the hot issue of material field due to their excellent mechanical and physical properties, e.g., high-specific strength and modulus, good wear resistance, and damping capacity. As compared with aluminum matrix composites, magnesium matrix composites have merit in their specific weight and have wide applications in aerospace and aeronautical fields. Generally, the processing techniques for magnesium matrix composites can be categorized as conventional and special processing routes. In recent years, as a special processing route, metal melt infiltration into porous ceramic preform featured by its low cost and availability of high-volume fraction of reinforced ceramics have been receiving much attention. Thus, in this review, one emphasis was put on the description of this processing technique in association with the means to obtain good wettability, the prerequisite for this kind of processing method. Based on the recognized fact that there exist clean interface and bonding ability between ceramics and matrix metal, in-situ reaction synthesis is usually utilized to fabricate magnesium matrix composites. Therefore, the interfacial feature was also reviewed for the in-situ reaction synthesis. Characterizations of microstructures and various mechanical-physical properties were finally summarized for magnesium matrix composites including tensile response, wear resistance, creep behavior, and damping capacity.
基金financially supported by the National Basic Research Program of China (Nos.2011CB932603 and 2012CB619600)the National Natural Science Foundation of China (No.51331008)
文摘Carbon nanotube-reinforced 2009Al （CNT/2009Al） composites with randomly oriented CNTs and aligned CNTs were fabricated by friction stir processing （FSP） and FSP-rolling, respectively. The CNT/2009A1 composites with aligned CNTs showed much better tensile properties at room temperature and elevated temperature compared with those with the randomly oriented CNTs, which is mainly attributed to larger equivalent aspect ratio of the CNTs and avoidance of preferential fracture problems. However, much finer grain size was not beneficial to obtaining high strength above 473 K. The aligned CNTs resulted in tensile anisotropy, with the best tensile properties being achieved along the direction of CNT aligning. As the off-axis angle increased, the tensile properties were reduced due to the weakening of the load transfer ability. Furthermore, aligned CNTs resulted in much lower coefficient of thermal expansion compared with randomly oriented CNTs.
基金the National Natural Science Foundation of China(Nos.U1760201,52034005,51974220)the Key Research and Development Program of Shaanxi Province,China(Nos.2020ZDLGY13-06,2017ZDXM-GY-037)+1 种基金the Innovation Capacity Support Project of Shaanxi Province-Nova Program,China(No.2020KJXX-077)the Science Fund for Distinguished Young Scholars in Universities of Shaanxi Province,China。
