Bodycote researchers have successfully demonstrated that a T6 heat treatment can be integrated with Densal?, a proprietary, aluminum specific, hot isostatic pressing (HIP) process. In this combined operation, at least...Bodycote researchers have successfully demonstrated that a T6 heat treatment can be integrated with Densal?, a proprietary, aluminum specific, hot isostatic pressing (HIP) process. In this combined operation, at least a portion of the solution heat treatment is conducted at elevated pressure. During development, two issues, adiabatic cooling during depressurization and a possible variation in the kinetics of homogenization resulting from conducting the solution heat treat at elevated pressure were perceived as factors which could alter the heat treat response from that seen in conventional processing. This paper reviews the results of experiments performed to Al-Si-Mg (A356.0) castings subjected to both combined and conventional processing routes. Results indicate that the combined HIP and heat treat process is an efficient means of achieving a microstructure characteristic of a conventionally T6 processed material while eliminating porosity within the casting. Further, the fatigue life of an A356.0 casting processed using the combined cycle can be improved by more than an order of magnitude over the as-cast and T6 treated component.展开更多
Castable glass ceramics based on SiO 2-Al 2O 3-K 2O-Na 2O system were prepared. The structure and physical properties of this material were tested and analyzed by x-ray, SEM and other methods. It was show that the maj...Castable glass ceramics based on SiO 2-Al 2O 3-K 2O-Na 2O system were prepared. The structure and physical properties of this material were tested and analyzed by x-ray, SEM and other methods. It was show that the major crystalline phase is leucite(KalSi 2O 6) and compressive and flexible strength is 420 MPa and 102 MPa respectively. Its character is almost similar to natural dental enamel. This material is an ideal dental repair material. The biological tests show that this material has a good biocompatibility and prospectives for developing.展开更多
Pulse current heating (PCH) was used to join Ti-6Al-4V alloy at two cases of with die and without die. Hot-pressing (HP) method was used to provide a comparison between the two methods. Microstructures near the contac...Pulse current heating (PCH) was used to join Ti-6Al-4V alloy at two cases of with die and without die. Hot-pressing (HP) method was used to provide a comparison between the two methods. Microstructures near the contacting surfaces were observed in optical microscope. Temperature distribution was analyzed. After joining, the tensile properties of the samples were evaluated. Experimental results show that grains and phases grow transversely on contacting surfaces, which makes two parts into a whole with a certain of tensile strength. PCH joining is a different temperature joining method. The highest temperature is located at the interface. The comparison of tensile strengths of samples joined by the two methods indicates that joining temperature and holding time needed by PCH are lower and less than those needed for HP.展开更多
This paper presents the results of equal channel angular pressing (ECAP) and subsequent heat treatment (HT) as a method to improve the wear resistance of metallic materials in friction sliding. The effect of ECAP and ...This paper presents the results of equal channel angular pressing (ECAP) and subsequent heat treatment (HT) as a method to improve the wear resistance of metallic materials in friction sliding. The effect of ECAP and HT on the microstructure and mechanical properties of low carbon steel is investigated in this work. The mechanisms of wear resistance of steel with ultrafine and nanostructures produced by equal-channel angular pressing is analyzed. The results show that ECAP at room temperature and annealing at 350°C and 450°C can be used as a technology of reducing wear in friction sliding.展开更多
文摘Bodycote researchers have successfully demonstrated that a T6 heat treatment can be integrated with Densal?, a proprietary, aluminum specific, hot isostatic pressing (HIP) process. In this combined operation, at least a portion of the solution heat treatment is conducted at elevated pressure. During development, two issues, adiabatic cooling during depressurization and a possible variation in the kinetics of homogenization resulting from conducting the solution heat treat at elevated pressure were perceived as factors which could alter the heat treat response from that seen in conventional processing. This paper reviews the results of experiments performed to Al-Si-Mg (A356.0) castings subjected to both combined and conventional processing routes. Results indicate that the combined HIP and heat treat process is an efficient means of achieving a microstructure characteristic of a conventionally T6 processed material while eliminating porosity within the casting. Further, the fatigue life of an A356.0 casting processed using the combined cycle can be improved by more than an order of magnitude over the as-cast and T6 treated component.
文摘Castable glass ceramics based on SiO 2-Al 2O 3-K 2O-Na 2O system were prepared. The structure and physical properties of this material were tested and analyzed by x-ray, SEM and other methods. It was show that the major crystalline phase is leucite(KalSi 2O 6) and compressive and flexible strength is 420 MPa and 102 MPa respectively. Its character is almost similar to natural dental enamel. This material is an ideal dental repair material. The biological tests show that this material has a good biocompatibility and prospectives for developing.
基金Project(50272047) supported by the National Natural Science Foundation of China
文摘Pulse current heating (PCH) was used to join Ti-6Al-4V alloy at two cases of with die and without die. Hot-pressing (HP) method was used to provide a comparison between the two methods. Microstructures near the contacting surfaces were observed in optical microscope. Temperature distribution was analyzed. After joining, the tensile properties of the samples were evaluated. Experimental results show that grains and phases grow transversely on contacting surfaces, which makes two parts into a whole with a certain of tensile strength. PCH joining is a different temperature joining method. The highest temperature is located at the interface. The comparison of tensile strengths of samples joined by the two methods indicates that joining temperature and holding time needed by PCH are lower and less than those needed for HP.
文摘This paper presents the results of equal channel angular pressing (ECAP) and subsequent heat treatment (HT) as a method to improve the wear resistance of metallic materials in friction sliding. The effect of ECAP and HT on the microstructure and mechanical properties of low carbon steel is investigated in this work. The mechanisms of wear resistance of steel with ultrafine and nanostructures produced by equal-channel angular pressing is analyzed. The results show that ECAP at room temperature and annealing at 350°C and 450°C can be used as a technology of reducing wear in friction sliding.
