If the main working parts are damaged during the use of the household mould, the manufactured workpiece will be unusable, so be sure to understand the following about the failure of the household mould when using the mould.
1. Thermal fatigue crack damage
Thermal fatigue cracking failure die-casting production, repeated stimulation of the household mould, cooling and heating effects, moulding surface and internal deformation are involved, and repeated cycling of thermal stress, resulting in damage and loss of the toughness of the tissue structure, resulting in cracks appearing and continue to expand, once Crack propagation, the effect of molten metal liquids, coupled with repeated mechanical stress cracks accelerated growth. Therefore, on the one hand, the die casting mould must be fully preheated to start. In addition, the die-casting mould must be kept within a certain temperature range during production to avoid early cracking. At the same time, to ensure that there are no internal problems in mould production and manufacturing. Because in actual production, most of the thermal fatigue cracking failure of the mould.
2. Invalid
Shooting fails under the action of the breaking force, dying at the weak point of the crack, especially when the scoring marks or electrical machining traces on the moulding surface polish the optics, or when the angle is moulded, fine cracks will first appear, and there are brittle phases or coarse grains And it is easy to break. And brittle fracture cracks grow rapidly, and mould failure is a very dangerous factor. Therefore, on the one hand, scratches on the mould surface, electrical machining traces must be polished, zinc die-casting, even if it is in the position of the casting system, it must also be polished. The mould material used has high strength and good plasticity, and the additional requirements for impact toughness and fracture toughness are good.
3. Corrosion failure
The melting failure has previously stated that the traditional die-casting alloys zinc alloys, aluminum alloys, magnesium alloys and copper alloys, but also pure die-casting aluminum, zinc, aluminum, and magnesium are relatively active metal elements, and they have good affinity with mould materials. Especially Al is easy to bite. When the mould hardness is high and the corrosion resistance is good, if it is soft, then the moulding surface is under adverse corrosion resistance.
There are many factors for household mould failure, both external factors (for example, whether the temperature of the die-casting mould is preheated, the amount of water-based paint sprayed, the die-casting machine, the tonnage of the mould size matching, the high-pressure brake speed is too fast, the cooling water is open and the die-casting production is synchronized, casting materials And parts, as appropriate, iron casting size, shape, size, coating type, etc.) wall thickness. There are internal (mould material metallurgical quality, forging process blanks, mould structure pouring system design, design, mould machine (EDM) internal stress generated during the processing of the process, the mould heat treatment is reasonable, the case of reasonable processing technology, Including a variety of matching accuracy and finish requirements). Early die failure, need to find out which internal or external, for future improvement. However, in actual production, corrosion only dies locally. A part of the gate (core, cavity) directly washed in the case of the gate is prone to corrosion, and the hardness of the soft aluminum alloy die-casting adhesive mould is prone to occur.