Die cast alloys have to be poured at temperatures much higher than their liquidus in order to make the alloys castable. Pouring at a high temperature reduces the formation of dendrites in the shot sleeve which tend to choke the flow at the in-gate but causes increased damage to the shot tooling and dies. Forming globular grains in the shot sleeve is an effective way of breaking the limit of fluidity on reducing the pouring temperature in order to increase die life and to improve the integrity of die casting products. This study investigated the feasibility of producing globular grains in a shot sleeve using a water-cooled ultrasound trough for feeding molten metal into the shot sleeve. Globular grains were obtained using this unique trough. The temperature window within which globular grains can be produced for E380 alloy was determined. Without using the WCUST, the grains in the shot sleeve were fully dendritic and the grain size was about 300 µm. When the molten metal was poured over the WCUST, small globular grains were obtained for the entire pouring temperature window, from 610 °C (1130 °F) to 700 °C (1292 °F), tested in this study. Analysis was made on the conditions for obtaining globular grains. The analysis seems in agreement with experimental results. In addition to producing globular grains for die casting applications, the water-cooled ultrasound trough may be suitable for grain refinement of other gravity casting processes.

压铸合金必须在远高于其液相线的温度下浇注，以使合金可浇注。高温浇注可减少压射套筒中枝晶的形成，枝晶往往会阻塞浇口处的流动，但会增加对压射工具和模具的损坏。在压射套内形成球状晶粒是打破流动性限制降低浇注温度以提高模具寿命和提高压铸产品完整性的有效方法。本研究调查了使用水冷超声波槽将熔融金属送入压射套筒中在压射套筒中产生球状晶粒的可行性。使用这种独特的槽获得了球形颗粒。确定了 E380 合金可以产生球状晶粒的温度窗口。在不使用 WCUST 的情况下，压射套筒中的晶粒完全是树枝状的，晶粒尺寸约为 300 µm。当熔融金属浇注在 WCUST 上时，在本研究中测试的整个浇注温度窗口（从 610 °C (1130 °F) 到 700 °C (1292 °F)）都获得了小的球状晶粒。对获得球状晶粒的条件进行了分析。该分析似乎与实验结果一致。除了为压铸应用生产球状晶粒外，水冷超声波槽还可适用于其他重力铸造工艺的晶粒细化。从 610 °C (1130 °F) 到 700 °C (1292 °F)，在本研究中进行了测试。对获得球状晶粒的条件进行了分析。该分析似乎与实验结果一致。除了为压铸应用生产球状晶粒外，水冷超声波槽还可适用于其他重力铸造工艺的晶粒细化。从 610 °C (1130 °F) 到 700 °C (1292 °F)，在本研究中进行了测试。对获得球状晶粒的条件进行了分析。该分析似乎与实验结果一致。除了为压铸应用生产球状晶粒外，水冷超声波槽还可适用于其他重力铸造工艺的晶粒细化。