Narrow Results

The process parameters were optimized by simulation and verification experiments using orthogonal experimental design and the Taguchi method to lessen the tendency of significant shrinkage porosity in the centrifugal cast ring parts of K417 nickel-based superalloy. Advanced Porosity Model (APM) in ProCAST was used to predict the shrinkage porosity of centrifugal castings, and the effects of centrifugal speed, pouring speed, pouring temperature and preheating temperature of the mold were investigated on the shrinkage porosity ratio of the castings. According to the results, the parameter that has the greatest influence on the shrinkage porosity ratio of centrifugal casting is the centrifuge speed, followed by the preheating temperature of the mold, and the pouring temperature and pouring speed have relatively small effects on it. The optimized parameters were proposed as follows: centrifugal speed of 500 r/min, pouring speed of 225 mm/s, pouring temperature of 1400${}^{\circ }$, and mold preheating temperature of 50${}^{\circ }$, which could effectively reduce the formation of shrinkage porosity of the K417 centrifugal casting rings.

Al-Cu alloy castings are obtained using centrifugal casting. The regularity of mechanical property gradient distribution of Al-Cu alloy castings with the same centrifugal radius at different positions is investigated. The result shows that the tensile strength, yield strength, elongation and microscope hardness exhibit the following gradient distribution characteristic — high on both sides and low on the center. The trend of mechanical property gradient distribution of Al-Cu alloy increases with the increase in the rotation speed. Moreover, the mechanical properties of casting centerline two sides have asymmetry. The reason is that the grain size of casting centerline two sides and Al₂Cu phase and Cu content change correspondingly.