Burning-on and methods of preventing it; Design and Process of Casting Aluminum Impellers for Hydraulic Torque Converters; Development of green sand mold process for thin heat resistance steel castings; Hydrogen ga...Burning-on and methods of preventing it; Design and Process of Casting Aluminum Impellers for Hydraulic Torque Converters; Development of green sand mold process for thin heat resistance steel castings; Hydrogen gas pick-up of Al-alloy melt during Lost Foam Casting; Improving environmental production performance of green sand release agents;Influence of sulfur on heterogeneous nucleus of spheroidal展开更多
The thixocasting process was chosen to produce the impellers as it is capable of producing castings with extremely high internal quality.Slugs cut from the DC cast bars are re-heated to the semi-solid casting temperat...The thixocasting process was chosen to produce the impellers as it is capable of producing castings with extremely high internal quality.Slugs cut from the DC cast bars are re-heated to the semi-solid casting temperature, and a specially-designed runner and gating system is used to prevent oxide from the surface of the slugs from becoming incorporated into the impeller.The technology used to produce the semi-solid impellers is described in detail.The semi-solid cast impellers, produced from an Al-Si-Mg-Cu alloy, are heat treated to the T6 temper.Results from testing are presented demonstrating that the impellers are free of porosity and other internal defects.Both mechanical property and fatigue data are presented showing that the semi-solid impellers have better properties than impellers produced by conventional casting and similar properties to forged and machined impellers.A short study is also described which identified suitable processing parameters to minimize hot tearing in the complex-shaped turbocharger impellers semi-solid cast from alloy 201.The surfaces of the impellers were examined using penetrant testing, and the results of modifying processing parameters on the propensity for surface cracking are presented.An aging study was performed to identify optimum mechanical strength.展开更多
文摘Burning-on and methods of preventing it; Design and Process of Casting Aluminum Impellers for Hydraulic Torque Converters; Development of green sand mold process for thin heat resistance steel castings; Hydrogen gas pick-up of Al-alloy melt during Lost Foam Casting; Improving environmental production performance of green sand release agents;Influence of sulfur on heterogeneous nucleus of spheroidal
文摘The thixocasting process was chosen to produce the impellers as it is capable of producing castings with extremely high internal quality.Slugs cut from the DC cast bars are re-heated to the semi-solid casting temperature, and a specially-designed runner and gating system is used to prevent oxide from the surface of the slugs from becoming incorporated into the impeller.The technology used to produce the semi-solid impellers is described in detail.The semi-solid cast impellers, produced from an Al-Si-Mg-Cu alloy, are heat treated to the T6 temper.Results from testing are presented demonstrating that the impellers are free of porosity and other internal defects.Both mechanical property and fatigue data are presented showing that the semi-solid impellers have better properties than impellers produced by conventional casting and similar properties to forged and machined impellers.A short study is also described which identified suitable processing parameters to minimize hot tearing in the complex-shaped turbocharger impellers semi-solid cast from alloy 201.The surfaces of the impellers were examined using penetrant testing, and the results of modifying processing parameters on the propensity for surface cracking are presented.An aging study was performed to identify optimum mechanical strength.