Cooling Behavior of A356 Alloy in Surfactant Quenching Medium

In this study, the cooling behavior of Sr-modified A356 alloy aluminum wheels produced by low-pressure die-casting technology was investigated in different quenching mediums. Water and surfactant quenchants were used in order to determine the cooling rate and mechanical properties of the alloy. A thermocouple was attached to the wheels, and parts were immersed into different quenching mediums after solution treatment. Data were collected by using a data logger. Tensile test and hardness test were carried out in order to determine the effect of quenching step on mechanical properties. Statistical analysis was performed, and graphics were drawn with Minitab. Maximum cooling rates throughout the quenching were obtained, respectively, 61–68–70–85 °C/s at SDS, Triton X-100, Tween 20 and water quenching medium. It was found that 61 °C/s is enough to suppress precipitation for artificially aging, and the cooling rate at Leidenfrost point is the most important parameter for correlation with mechanical properties. According to the hypothesis analysis, only yield strength values were affected by the quenching rate at LDP statistically.