Injection mechanism is important for filling and forming in squeeze casting equipment. The fit clearance of its components greatly affects the accuracy and stability in the injection process. To minimize the change of fitting clearance during injection

a multi-objective optimization method based on the Kriging metamodel was proposed which taken into account for the clearance rate and temperature difference as the objectives

and considered the key parameters of the injection mechanism and process such as initial clearance and pouring temperature. The results show that the accuracy of Kriging metamodel is higher than 0.97. Meanwhile

the optimized process parameters were presented as follows: casting pouring temperature of 701 ℃

shot-sleeve preheating temperature of 338 ℃

shot-sleeve wall thickness of 16 mm

initial clearance of 0.1061 mm and injection velocity of 56 mm/s

where the clearance rate is reduced by 10% and the heat transfer temperature difference is reduced by 49% after optimization. In addition

the filling process is more stable.