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Wenchi Chen - One of the best experts on this subject based on the ideXlab platform.
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effects of t6 heat treatment on thermal stability and wear behaviour of al 12 5si 4 5cu 1 0mg Alloy
Materials Science and Technology, 2012Co-Authors: Chinpyng Wu, Wenchi ChenAbstract:AbstractThe present study elucidates how T6 heat treatment affects thermal stability and wear behaviour of Al–12·5Si–4·5Cu–1·0Mg Alloy. The experimental Alloys under as Cast and T6 heat treated conditions were isothermally heat treated at 300°C for 100 h to investigate thermal stability and wear behaviour. Owing to the precipitation of a large amount of λ′ (Al5Cu2Mg8Si6) and θ′ (Al2Cu) phases, T6 heat treated Alloy showed the highest hardness before isothermal heat treatment. The coarsening of λ′ and θ′ phases led to a large decrease in hardness following isothermal heat treatment. The thermal stability of the T6 heat treated Alloy was much worse than that of the as Cast Alloy. For wear behaviour, the as Cast and T6 heat treated Alloys showed the same wear rate with 10 N load after isothermal heat treatment, which indicated that the wear rates of Al–12·5Si–4·5Cu–1·0Mg Alloys were independent on T6 heat treatment. Under 40 N load, the wear resistance of as Cast Alloy was superior to that of T6 heat treated...
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Effects of T6 heat treatment on thermal stability and wear behaviour of Al–12·5Si–4·5Cu–1·0Mg Alloy
Materials Science and Technology, 2012Co-Authors: Chinpyng Wu, Wenchi ChenAbstract:AbstractThe present study elucidates how T6 heat treatment affects thermal stability and wear behaviour of Al–12·5Si–4·5Cu–1·0Mg Alloy. The experimental Alloys under as Cast and T6 heat treated conditions were isothermally heat treated at 300°C for 100 h to investigate thermal stability and wear behaviour. Owing to the precipitation of a large amount of λ′ (Al5Cu2Mg8Si6) and θ′ (Al2Cu) phases, T6 heat treated Alloy showed the highest hardness before isothermal heat treatment. The coarsening of λ′ and θ′ phases led to a large decrease in hardness following isothermal heat treatment. The thermal stability of the T6 heat treated Alloy was much worse than that of the as Cast Alloy. For wear behaviour, the as Cast and T6 heat treated Alloys showed the same wear rate with 10 N load after isothermal heat treatment, which indicated that the wear rates of Al–12·5Si–4·5Cu–1·0Mg Alloys were independent on T6 heat treatment. Under 40 N load, the wear resistance of as Cast Alloy was superior to that of T6 heat treated...
Michael S Mccracken - One of the best experts on this subject based on the ideXlab platform.
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Comparison of the Passivity between Cast Alloy and Laser‐Welded Titanium Overdenture Bars
Journal of Prosthodontics, 2009Co-Authors: Jose Paiva, Daniel A. Givan, Janet C. Broome, Jack E. Lemons, Michael S MccrackenAbstract:Purpose: The purpose of this study was to investigate the fit of Cast Alloy overdenture and laser-welded titanium-Alloy bars by measuring induced strain upon tightening of the bars on a master Cast as well as a function of screw tightening sequence. Materials and Methods: Four implant analogs were secured into Type IV dental stone to simulate a mandibular edentulous patient Cast, and two groups of four overdenture bars were fabricated. Group I was four Cast Alloy bars and Group II was four laser-welded titanium bars. The Cast Alloy bars included Au–Ag–Pd, Pd–Ag–Au, Au–Ag–Cu–Pd, and Ag–Pd–Cu-Au, while the laser-welded bars were all Ti–Al–V Alloy. Bars were made from the same master Cast, were torqued into place, and the total strain in the bars was measured through five strain gauges bonded to the bar between the implants. Each bar was placed and torqued 27 times to 30 Ncm per screw using three tightening sequences. Data were processed through a strain amplifier and analyzed by computer using StrainSmart software. Data were analyzed by ANOVA and Tukey's post hoc test. Results: Significant differences were found between Alloy types. Laser-welded titanium bars tended to have lower strains than corresponding Cast bars, although the Au–Ag–Pd bar was not significantly different. The magnitudes of total strain were the least when first tightening the ends of the bar. Conclusions: The passivity of implant overdenture bars was evaluated using total strain of the bar when tightening. Selecting a high modulus of elasticity Cast Alloy or use of laser-welded bar design resulted in the lowest average strain magnitudes. While the effect of screw tightening sequence was minimal, tightening the distal ends first demonstrated the lowest strain, and hence the best passivity.
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Comparison of the Passivity between Cast Alloy and Laser-Welded Titanium Overdenture Bars
Journal of prosthodontics : official journal of the American College of Prosthodontists, 2009Co-Authors: Jose Paiva, Daniel A. Givan, Janet C. Broome, Jack E. Lemons, Michael S MccrackenAbstract:The purpose of this study was to investigate the fit of Cast Alloy overdenture and laser-welded titanium-Alloy bars by measuring induced strain upon tightening of the bars on a master Cast as well as a function of screw tightening sequence. Four implant analogs were secured into Type IV dental stone to simulate a mandibular edentulous patient Cast, and two groups of four overdenture bars were fabricated. Group I was four Cast Alloy bars and Group II was four laser-welded titanium bars. The Cast Alloy bars included Au-Ag-Pd, Pd-Ag-Au, Au-Ag-Cu-Pd, and Ag-Pd-Cu-Au, while the laser-welded bars were all Ti-Al-V Alloy. Bars were made from the same master Cast, were torqued into place, and the total strain in the bars was measured through five strain gauges bonded to the bar between the implants. Each bar was placed and torqued 27 times to 30 Ncm per screw using three tightening sequences. Data were processed through a strain amplifier and analyzed by computer using StrainSmart software. Data were analyzed by ANOVA and Tukey's post hoc test. Significant differences were found between Alloy types. Laser-welded titanium bars tended to have lower strains than corresponding Cast bars, although the Au-Ag-Pd bar was not significantly different. The magnitudes of total strain were the least when first tightening the ends of the bar. The passivity of implant overdenture bars was evaluated using total strain of the bar when tightening. Selecting a high modulus of elasticity Cast Alloy or use of laser-welded bar design resulted in the lowest average strain magnitudes. While the effect of screw tightening sequence was minimal, tightening the distal ends first demonstrated the lowest strain, and hence the best passivity.
Chinpyng Wu - One of the best experts on this subject based on the ideXlab platform.
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effects of t6 heat treatment on thermal stability and wear behaviour of al 12 5si 4 5cu 1 0mg Alloy
Materials Science and Technology, 2012Co-Authors: Chinpyng Wu, Wenchi ChenAbstract:AbstractThe present study elucidates how T6 heat treatment affects thermal stability and wear behaviour of Al–12·5Si–4·5Cu–1·0Mg Alloy. The experimental Alloys under as Cast and T6 heat treated conditions were isothermally heat treated at 300°C for 100 h to investigate thermal stability and wear behaviour. Owing to the precipitation of a large amount of λ′ (Al5Cu2Mg8Si6) and θ′ (Al2Cu) phases, T6 heat treated Alloy showed the highest hardness before isothermal heat treatment. The coarsening of λ′ and θ′ phases led to a large decrease in hardness following isothermal heat treatment. The thermal stability of the T6 heat treated Alloy was much worse than that of the as Cast Alloy. For wear behaviour, the as Cast and T6 heat treated Alloys showed the same wear rate with 10 N load after isothermal heat treatment, which indicated that the wear rates of Al–12·5Si–4·5Cu–1·0Mg Alloys were independent on T6 heat treatment. Under 40 N load, the wear resistance of as Cast Alloy was superior to that of T6 heat treated...
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Effects of T6 heat treatment on thermal stability and wear behaviour of Al–12·5Si–4·5Cu–1·0Mg Alloy
Materials Science and Technology, 2012Co-Authors: Chinpyng Wu, Wenchi ChenAbstract:AbstractThe present study elucidates how T6 heat treatment affects thermal stability and wear behaviour of Al–12·5Si–4·5Cu–1·0Mg Alloy. The experimental Alloys under as Cast and T6 heat treated conditions were isothermally heat treated at 300°C for 100 h to investigate thermal stability and wear behaviour. Owing to the precipitation of a large amount of λ′ (Al5Cu2Mg8Si6) and θ′ (Al2Cu) phases, T6 heat treated Alloy showed the highest hardness before isothermal heat treatment. The coarsening of λ′ and θ′ phases led to a large decrease in hardness following isothermal heat treatment. The thermal stability of the T6 heat treated Alloy was much worse than that of the as Cast Alloy. For wear behaviour, the as Cast and T6 heat treated Alloys showed the same wear rate with 10 N load after isothermal heat treatment, which indicated that the wear rates of Al–12·5Si–4·5Cu–1·0Mg Alloys were independent on T6 heat treatment. Under 40 N load, the wear resistance of as Cast Alloy was superior to that of T6 heat treated...
Jose Paiva - One of the best experts on this subject based on the ideXlab platform.
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Comparison of the Passivity between Cast Alloy and Laser‐Welded Titanium Overdenture Bars
Journal of Prosthodontics, 2009Co-Authors: Jose Paiva, Daniel A. Givan, Janet C. Broome, Jack E. Lemons, Michael S MccrackenAbstract:Purpose: The purpose of this study was to investigate the fit of Cast Alloy overdenture and laser-welded titanium-Alloy bars by measuring induced strain upon tightening of the bars on a master Cast as well as a function of screw tightening sequence. Materials and Methods: Four implant analogs were secured into Type IV dental stone to simulate a mandibular edentulous patient Cast, and two groups of four overdenture bars were fabricated. Group I was four Cast Alloy bars and Group II was four laser-welded titanium bars. The Cast Alloy bars included Au–Ag–Pd, Pd–Ag–Au, Au–Ag–Cu–Pd, and Ag–Pd–Cu-Au, while the laser-welded bars were all Ti–Al–V Alloy. Bars were made from the same master Cast, were torqued into place, and the total strain in the bars was measured through five strain gauges bonded to the bar between the implants. Each bar was placed and torqued 27 times to 30 Ncm per screw using three tightening sequences. Data were processed through a strain amplifier and analyzed by computer using StrainSmart software. Data were analyzed by ANOVA and Tukey's post hoc test. Results: Significant differences were found between Alloy types. Laser-welded titanium bars tended to have lower strains than corresponding Cast bars, although the Au–Ag–Pd bar was not significantly different. The magnitudes of total strain were the least when first tightening the ends of the bar. Conclusions: The passivity of implant overdenture bars was evaluated using total strain of the bar when tightening. Selecting a high modulus of elasticity Cast Alloy or use of laser-welded bar design resulted in the lowest average strain magnitudes. While the effect of screw tightening sequence was minimal, tightening the distal ends first demonstrated the lowest strain, and hence the best passivity.
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Comparison of the Passivity between Cast Alloy and Laser-Welded Titanium Overdenture Bars
Journal of prosthodontics : official journal of the American College of Prosthodontists, 2009Co-Authors: Jose Paiva, Daniel A. Givan, Janet C. Broome, Jack E. Lemons, Michael S MccrackenAbstract:The purpose of this study was to investigate the fit of Cast Alloy overdenture and laser-welded titanium-Alloy bars by measuring induced strain upon tightening of the bars on a master Cast as well as a function of screw tightening sequence. Four implant analogs were secured into Type IV dental stone to simulate a mandibular edentulous patient Cast, and two groups of four overdenture bars were fabricated. Group I was four Cast Alloy bars and Group II was four laser-welded titanium bars. The Cast Alloy bars included Au-Ag-Pd, Pd-Ag-Au, Au-Ag-Cu-Pd, and Ag-Pd-Cu-Au, while the laser-welded bars were all Ti-Al-V Alloy. Bars were made from the same master Cast, were torqued into place, and the total strain in the bars was measured through five strain gauges bonded to the bar between the implants. Each bar was placed and torqued 27 times to 30 Ncm per screw using three tightening sequences. Data were processed through a strain amplifier and analyzed by computer using StrainSmart software. Data were analyzed by ANOVA and Tukey's post hoc test. Significant differences were found between Alloy types. Laser-welded titanium bars tended to have lower strains than corresponding Cast bars, although the Au-Ag-Pd bar was not significantly different. The magnitudes of total strain were the least when first tightening the ends of the bar. The passivity of implant overdenture bars was evaluated using total strain of the bar when tightening. Selecting a high modulus of elasticity Cast Alloy or use of laser-welded bar design resulted in the lowest average strain magnitudes. While the effect of screw tightening sequence was minimal, tightening the distal ends first demonstrated the lowest strain, and hence the best passivity.
T. Takahashi - One of the best experts on this subject based on the ideXlab platform.
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Joint properties of friction welded joint between 6061 Al Alloy pipe and Al-Si12CuNi (AC8A) Al Cast Alloy pipe
The International Journal of Advanced Manufacturing Technology, 2016Co-Authors: M Kimura, Michimi Kusaka, Hitoshi Sakaguchi, Koichi Kaizu, T. TakahashiAbstract:This paper describes the joint properties of the friction welded joint between 6061 (AA6061) Al Alloy pipe and Al-Si12CuNi (AC8A) Al Cast Alloy pipe. When joints were made with a friction pressure of 25 MPa, a friction speed of 27.5 rps, and a forge pressure of 30 MPa, the joint strength increased with increasing friction time, and it was approximately 40 % of the ultimate tensile strength of the AC8A base metal at a friction time of 2.0 s. However, all joints fractured at the weld interface between the AA6061 side and the AC8A side, which had an AC8A adhering to the weld interface on the AA6061 side (mixed-mode fracture). When joints were made at a friction time of 0.3 s with the same friction pressure and friction speed, the joint strength increased with increasing forge pressure, and it was approximately 60 % of the AC8A base metal at a forge pressure of 175 MPa. Many joints had the fracture at the AC8A side although one of the joints had at the mixed-mode fracture. On the other hand, when joints were made at friction times of 0.7 and 2.0 s, the joint strength was approximately 60 % of the AC8A base metal at a forge pressure of 75 MPa. Those joints fractured on the AC8A side, because the adjacent region of the weld interface was softened. In addition, the flash of the joint with a friction time of 0.7 s was fewer than that of 2.0 s. To obtain the joint with the fracture from the AC8A side, the joint should be made with the opportune friction time such as 0.7 s and the opportune forge pressure such as 75 MPa because this joint had no cracks at the weld interface.
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Characteristics of Friction Welding Between Solid Bar of 6061 Al Alloy and Pipe of Al-Si12CuNi Al Cast Alloy
Journal of Materials Engineering and Performance, 2015Co-Authors: M Kimura, Michimi Kusaka, Hitoshi Sakaguchi, Koichi Kaizu, T. TakahashiAbstract:This paper describes the characteristics of friction welding between a solid bar of 6061 Al Alloy and a pipe of Al-Si12CuNi (AC8A) Al Cast Alloy. When the joint was made by a continuous drive friction welding machine (conventional method), the AC8A portion of the joint showed heavy deformation and the AA6061 showed minimal deformation. In particular, the joint could not be successfully made with following conditions, because AC8A pipe side crushed due to insufficient friction heat or high pressure: a short friction time such as 0.3 s, high friction pressure such as 100 MPa, or high forge pressure such as 150 MPa. The heavy deformation of AC8A side was caused by increasing friction torque during braking. To prevent braking deformation until rotation stops, a joint was made by a continuous drive friction welding machine that has an electromagnetic clutch. When the clutch was released, the relative speed between both specimens simultaneously decreased to zero. When the joint was made with friction pressure of 25 MPa, friction time of 0.3 s, and forge pressure of 125 MPa, the joining could be successfully achieved and that had approximately 16% efficiency. In addition, when the joint was made with friction pressure of 25 MPa, friction time of 0.7 s, and forge pressure of 125 MPa, it had approximately 54% efficiency. However, all joints showed the fracture between the traveled weld interface and the AC8A side, because the weld interface traveled in the longitudinal direction of AC8A side from the first contacted position of both weld faying surfaces. Hence, it was clarified that the friction welding between a solid bar of AA6061 and a Cast pipe of AC8A was not desirable since the traveling phenomena of the weld interface were caused by the combination of the shapes of the friction welding specimens.