Crack formation is one of the most common and fatal defects of sow molds and dross pans during long-term service in aluminum alloy ingot production. Once large and penetrating cracks appear on these tooling components, they can no longer meet production safety and product quality standards and have to be replaced completely. Such failures are mainly caused by thermal fatigue. Repeated rapid heating and cooling cycles in the casting process generate alternating thermal stress on the surface and interior of sow molds and dross pans, making thermal fatigue cracks practically unavoidable in conventional production scenarios.
Effectively alleviating and delaying crack initiation and propagation is critical to extending the service life of sow molds and dross pans. Longer tooling service cycles can significantly reduce the frequency of equipment replacement, cut down overall production and maintenance costs, and ultimately lower the fixed production cost per kilogram of finished aluminum alloy ingots, bringing substantial economic benefits to industrial mass production.
To fundamentally mitigate thermal fatigue cracks, our team focuses on multi-dimensional optimization covering material selection, structural design, casting process adjustment and quality inspection control. In terms of structural optimization, we conduct finite element stress analysis on vulnerable crack areas of sow molds and dross pans. By optimizing the local structure, fillet transition and wall thickness distribution of stress-concentrated parts, we effectively disperse alternating thermal stress and avoid stress accumulation that triggers crack generation.
For material improvement, we continuously develop, screen and test new high-temperature and fatigue-resistant alloy materials. We select high-quality raw materials with excellent thermal stability, toughness and thermal fatigue resistance matching the actual casting working conditions, so as to enhance the inherent crack resistance of the tooling itself. In addition, we optimize the whole pouring and cooling process parameters, including pouring temperature, casting speed and cooling water flow rate, to reduce severe temperature fluctuations and thermal shock on molds and pans during production.
Furthermore, we add strict non-destructive testing procedures including Ultrasonic Testing (UT) and Magnetic Particle Testing (MT) in the pre-production and regular in-service inspection stages. These testing methods can accurately detect tiny internal and surface micro-cracks, material inhomogeneities and potential defect risks at an early stage. Timely elimination and repair of potential crack-inducing factors can greatly delay the expansion of fatigue cracks and ensure the stable and long-term operation of sow molds and dross pans.