First, mold materials and manufacturing quality. The selection of mold materials is fundamental. High-quality alloy tool steels (such as H13 and SKD61) are heat-resistant, wear-resistant, and have a long service life. Poor-quality steels with many impurities are prone to early cracking and wear. The success of heat treatment (quenching and tempering) determines the hardness and toughness of the mold. Insufficient hardness leads to easy wear, while insufficient toughness makes it prone to breaking under impact. Processing accuracy (such as the surface finish of the cavity and assembly clearance) also affects the stress-bearing quality of the mold. A rough surface is likely to cause stress concentration and shorten the service life.
Second, usage and maintenance conditions. The rationality of process parameters (such as molten metal temperature, injection pressure, and mold opening/closing speed) is crucial. High temperatures can easily cause thermal fatigue of the mold, and high pressure can easily cause damage to the mold cavity. The smoothness of mold cooling, as well as the flow rate and distribution of cooling water, affect thermal balance. Poor cooling can easily cause overheating and deformation of the mold. Inadequate daily maintenance (such as cleaning of cavity residues, application of release agent, and inspection of wear on guide pillars and bushes) will cause accumulated damage to the mold during use and accelerate aging.
Third, the rationality of product structure and mold structure design. Unreasonable mold structures (such as cavity corners being sharp instead of rounded, uneven wall thickness leading to local stress concentration, and unreasonable gate positions causing severe scouring by molten metal) will result in excessive local pressure or uneven heating during die casting, which is prone to cracks and collapses. The complexity of the product structure (deep cavities, thin walls, complex parting surfaces) will also increase mold wear. The more complex the mold, the more uneven the stress on the cavity, the more uneven the wear, and the shorter the mold life.
