Effect of Insulation and Static Time on the Uniformity of Aluminum Melt and Ingot Quality-1

The process of aluminum alloy melting includes multiple steps such as ingredient melting, alloying, stirring to remove impurities, refining to remove gas, etc. Under the action of intense stirring, chemical reactions, and temperature fluctuations, high-temperature melts inevitably produce non-uniform states such as spatial compositional differences, temperature gradients, and suspended residual gases and inclusions. The insulation and static process, as the last control process before melt casting, plays a core role in eliminating non steady state defects generated during the melting process by relying on the physical mechanisms of natural diffusion, gravity settling, and buoyancy sorting of the melt in a constant temperature and closed environment. It achieves global uniformity of melt composition, temperature, and purity, and provides stable and high-quality metallurgical raw materials for the subsequent DC casting solidification process.

The insulation settling time is the core variable that determines the settling effect. Compared with parameters such as settling temperature and furnace environment, it has stronger controllability and a more direct impact on the molten state. When the settling time is insufficient, the internal components of the melt will diffuse, inclusions will settle, and gas will not escape sufficiently. Residual component segregation, temperature fluctuations, and fine inclusions will directly enter the casting process, inducing internal defects in the ingot; When the static time is too long, the high-temperature melt will remain in a constant temperature static state for a long time, which will cause problems such as agglomeration of grain precursors, secondary oxidation of the melt, burning of alloy elements, and re dissolution of supersaturated gases. Instead, it will deteriorate the quality of the melt, leading to coarsening of the ingot structure and performance degradation. At present, domestic and foreign research mainly focuses on the influence of casting process parameters on ingot defects. Research on the insulation and static time is mostly focused on the process debugging of single alloys, and systematic research on the melt control mechanism, defect evolution law, and multi alloy adaptation characteristics of different static times is relatively scarce. In industrial production, there is a common problem of blind setting of static time and poor parameter adaptability, which makes it difficult to fully play the quality control role of static processes.