The normal T6 heat treatment process for cast A356 alloy generally requires about 15 h. This longperiod procedure increases greatly the manufacturing cost and decreases the productivity in practical production. In thi...The normal T6 heat treatment process for cast A356 alloy generally requires about 15 h. This longperiod procedure increases greatly the manufacturing cost and decreases the productivity in practical production. In this study, a new short-time heat treatment process with only 30 min solution time at 540℃ was developed for the production of motorcycle wheel hubs in order to reduce heat treatment time. Comparisons on microstructure evaluation and mechanical properties, such as tensile strength and ductility, were made between this new fast process and the conventional T6 heat treatment. The results revealed that this new heat treatment process enabled the spheroidization of the eutectic silicon thoroughly, while minimizing the growth of eutectic silicon. The A356 alloy after this new short-time heat treatment shows nearly equal mechanical properties compared with the same alloy heat treated in a normal T6 heat treatment. This investigation makes it possible to significantly improve the efficiency of heat treatment on A356 alloy and, at the same time, improve the mechanical properties of the alloy.展开更多
In this paper,by using an extension of Mawhin’s continuation theorem and some analysis methods,we study the existence of periodic solutions for the following prescribed mean curvature system d/dtφ(x')+▽W(x)=p(t...In this paper,by using an extension of Mawhin’s continuation theorem and some analysis methods,we study the existence of periodic solutions for the following prescribed mean curvature system d/dtφ(x')+▽W(x)=p(t), where x∈R^n,W∈C^1(R^n,R),p∈C(R,R^n)is T-periodic and φ(x)=x/√1+|x|^2.展开更多
基金financially supported by the National Natural Science Foundation of China under project 51574129
文摘The normal T6 heat treatment process for cast A356 alloy generally requires about 15 h. This longperiod procedure increases greatly the manufacturing cost and decreases the productivity in practical production. In this study, a new short-time heat treatment process with only 30 min solution time at 540℃ was developed for the production of motorcycle wheel hubs in order to reduce heat treatment time. Comparisons on microstructure evaluation and mechanical properties, such as tensile strength and ductility, were made between this new fast process and the conventional T6 heat treatment. The results revealed that this new heat treatment process enabled the spheroidization of the eutectic silicon thoroughly, while minimizing the growth of eutectic silicon. The A356 alloy after this new short-time heat treatment shows nearly equal mechanical properties compared with the same alloy heat treated in a normal T6 heat treatment. This investigation makes it possible to significantly improve the efficiency of heat treatment on A356 alloy and, at the same time, improve the mechanical properties of the alloy.
基金supported by the National Natural Science Foundation of China(No.11901004)the Natural Science Foundation of Anhui Province(No.1908085QA02)+1 种基金the Key Program of Scientific Research Fund for Young Teachers of AUST(No.QN2018109)sponsored by the National Natural Science Foundation of China(No.11271197)。
文摘In this paper,by using an extension of Mawhin’s continuation theorem and some analysis methods,we study the existence of periodic solutions for the following prescribed mean curvature system d/dtφ(x')+▽W(x)=p(t), where x∈R^n,W∈C^1(R^n,R),p∈C(R,R^n)is T-periodic and φ(x)=x/√1+|x|^2.
