Effects of melt flow and temperature on the macro and microstructure of scroll compressor in direct squeeze casting

Orbiting scroll compressors were successfully manufactured by direct squeeze casting. Solidification and melt flow of B390 alloy in an orbiting scroll compressor die has been simulated using a 3D-FVM code which takes full account of coupled heat and melt flow. Defect formation of the orbiting scroll compressor during squeeze casting has been investigated. Experimental results give a critical melt temperature of 600°C for sound castings, whereas this critical temperature is even below the liquidus temperature. These abnormal filling behaviors were attributed to complicated die geometry in conjunction with time delay prior to pressurization. This melt flow phenomena could be explained by the calculation results. The effect of the melt temperature on the microstructures and mechanical properties of the orbiting scroll compressor are also discussed.