Die Casting Mould Mechanical Properties Have Been Significantly Improved

Die-casting mold is a method of casting liquid die forging, a process in a dedicated die-casting die forging. Its basic process is: metal liquid first low-speed or high-speed casting filling into the mold cavity, the mold has a movable cavity surface, it is with the metal liquid cooling process forging, both to eliminate the shrinkage of the blank Loose defects, but also to the internal structure of the blank to achieve forging the broken grain. The overall mechanical properties of the blanks are significantly improved.

Die-casting mold failure for the following reasons:

01 thermal fatigue cracking failure failure

Mold in the production of die-casting, repeated by the role of cold and hot, forming the surface and its internal deformation, involving each other and repeated the thermal stress, resulting in damage to the structure of the two structures and loss of toughness, triggering the emergence of micro-cracks, and continue to expand , Once the crack is expanded, there are molten metal liquid squeeze, coupled with repeated mechanical stress to accelerate the expansion of the crack. To this end, on the one hand die die must be fully warmed. In addition, in the die-casting process, the mold must be kept in a certain operating temperature range, so as to avoid early cracking failure. At the same time, to ensure that the mold before production and manufacturing of internal factors do not occur. Due to actual production, most of the mold failure is thermal fatigue cracking failure.

02 fragmentation failure

In the role of the pressure of the mold, the mold will be the most weak in the initiation of cracks, especially the mold forming surface of the scribe marks or electrical processing marks are not polished light, or the formation of the clear angle will be the first subtle cracks ,Die Casting Mould  When the grain boundary there is brittle phase or coarse grain, it is easy to break. And the brittle fracture crack propagation is very fast, which is the fracture of the mold failure is a very dangerous factor. To this end, on the one hand where the scratches on the mold surface, electrical processing traces must be polished, even if it is in the casting system parts, must also be lighted. Also require the use of the mold material of high strength, good plasticity, impact toughness and fracture toughness are good.

03 dissolution failure

Commonly used die-casting alloys are zinc alloy, aluminum alloy, magnesium alloy and copper alloy, there are pure aluminum die-casting, Zn, Al, Mg is more active metal elements, they have good affinity with the mold material, mold. When the mold hardness is high, then the corrosion resistance is better, and the molding surface if the soft point, then the corrosion resistance.

Common failure analysis method of die - casting mold

In order to extend the service life of the mold, save costs and improve production efficiency, we must study the mold failure form and lead to mold failure reasons and die failure of the internal mechanism. As the reasons for the failure of die-casting mold is more complex, from the mold design, material selection, working conditions and many other aspects to be analyzed.

Analysis of Surface Morphology and Crack Propagation of Cracks

1Failure mold cavity surface is mainly erosion pits, the size is relatively uniform, the parts of the riser has obvious erosion pits, the surface has a certain direction of the scratches,Die Casting Mould  scratches on the distribution of the size of the aluminum alloy block Things. As the gate is directly on the metal parts of the erosion, the site has a clear flushing furrow, and can be observed between the cracks between the cracks. The crack starts from the crack source and expands to the west. There are a lot of cracks in the cracks, crack cracks have secondary cracks. As the mold use time is short, the general parts of the surface is mainly erosion pits and welding, and the gate of the main parts of the liquid metal erosion formed by the furrow and thermal fatigue cracks.