In this study,a mathematical model was developed to optimize the heat treatment process for maximum tensile strength and ductility of aluminum(8011) silicon carbide particulate composites.The process parameters are so...In this study,a mathematical model was developed to optimize the heat treatment process for maximum tensile strength and ductility of aluminum(8011) silicon carbide particulate composites.The process parameters are solutionizing time,aging temperature,and aging time.The experiments were performed on an universal testing machine according to centre rotatable design matrix.A mathematical model was developed with the main and interactive effects of the parameters considered.The analysis of variance technique was used to check the adequacy of the developed model.The optimum parameters were obtained for maximum tensile strength.Fractographic examination shows the cracks and dimples on the fractured surfaces of heat-treated specimen.展开更多
Most conventional ceramic based aluminum metal matrix composites(MMCs) are either heavy,costly or combination of both. In order to reduce cost and weight,while at the same time maintaining quality,cow horn particles(C...Most conventional ceramic based aluminum metal matrix composites(MMCs) are either heavy,costly or combination of both. In order to reduce cost and weight,while at the same time maintaining quality,cow horn particles(CHp) was used with aluminum alloy A356 to produce MMC for brake drum application and other engineering uses. The aim of this research is to model the age hardening process of the produced composite using response surface methodology(RSM) and artificial neural network(ANN),and to use the developed ANN as fitness function for a simulated annealing optimization algorithm(SA-NN system) for optimization of age hardening process parameters. The results show that ANN modeled the age hardening data excellently and better than RSM with a correlation coefficient of experimental response with ANN predictions being 0.9921 as against 0.9583 for the RSM. The SA-NN system optimized process parameters were in very close agreement with the experimental values with the maximum relative error of 1.2%,minimum of 0.35% and average of 0.71%.展开更多
运用触点材料测试系统进行了AgSnO2电接触材料在低压直流条件下的电接触实验，研究了材料转移情况，分析了电弧侵蚀形貌和成分变化。结果表明：AgSnO2（12）的转移方向为阴极向阳极转移，阴、阳极材料转移速率均为初期较快后逐渐减缓。...运用触点材料测试系统进行了AgSnO2电接触材料在低压直流条件下的电接触实验，研究了材料转移情况，分析了电弧侵蚀形貌和成分变化。结果表明：AgSnO2（12）的转移方向为阴极向阳极转移，阴、阳极材料转移速率均为初期较快后逐渐减缓。阴、阳极表面可按电弧侵蚀形貌分成对应的三个圆环状区域：中心A区—电弧作用域，B区—电弧影响区，最外层区—电弧无明显影响区。阴极电弧作用区微观形貌主要为海绵状基体上分布着大小不一的孔洞，Sn 和 O 元素多偏聚在孔洞区域；阳极侵蚀区主要为熔融流动铺层或喷溅状态。展开更多
文摘In this study,a mathematical model was developed to optimize the heat treatment process for maximum tensile strength and ductility of aluminum(8011) silicon carbide particulate composites.The process parameters are solutionizing time,aging temperature,and aging time.The experiments were performed on an universal testing machine according to centre rotatable design matrix.A mathematical model was developed with the main and interactive effects of the parameters considered.The analysis of variance technique was used to check the adequacy of the developed model.The optimum parameters were obtained for maximum tensile strength.Fractographic examination shows the cracks and dimples on the fractured surfaces of heat-treated specimen.
文摘Most conventional ceramic based aluminum metal matrix composites(MMCs) are either heavy,costly or combination of both. In order to reduce cost and weight,while at the same time maintaining quality,cow horn particles(CHp) was used with aluminum alloy A356 to produce MMC for brake drum application and other engineering uses. The aim of this research is to model the age hardening process of the produced composite using response surface methodology(RSM) and artificial neural network(ANN),and to use the developed ANN as fitness function for a simulated annealing optimization algorithm(SA-NN system) for optimization of age hardening process parameters. The results show that ANN modeled the age hardening data excellently and better than RSM with a correlation coefficient of experimental response with ANN predictions being 0.9921 as against 0.9583 for the RSM. The SA-NN system optimized process parameters were in very close agreement with the experimental values with the maximum relative error of 1.2%,minimum of 0.35% and average of 0.71%.
文摘运用触点材料测试系统进行了AgSnO2电接触材料在低压直流条件下的电接触实验，研究了材料转移情况，分析了电弧侵蚀形貌和成分变化。结果表明：AgSnO2（12）的转移方向为阴极向阳极转移，阴、阳极材料转移速率均为初期较快后逐渐减缓。阴、阳极表面可按电弧侵蚀形貌分成对应的三个圆环状区域：中心A区—电弧作用域，B区—电弧影响区，最外层区—电弧无明显影响区。阴极电弧作用区微观形貌主要为海绵状基体上分布着大小不一的孔洞，Sn 和 O 元素多偏聚在孔洞区域；阳极侵蚀区主要为熔融流动铺层或喷溅状态。
