Friday 9 September 2016

High scope of Die-casting machines abroad

The die-casting machines incurs huge cost on their equipment, set-up and processing. However, because of the simple processing methods, the incremental cost of each item is kept low but only in the case where large production is involved. Hence the global demand of die-casting machines is increasing among the casting manufacturers provided the die-casting fulfills good surface finish and dimensional accuracy.

There are two options for the manufacturers to obtain the machine from Die-Casting Machine Exporters, those are:

Pore-free die-casting – eliminate gas porosity defects

Direct Injection die-casting – Zinc castings reduce scrap and increase yield

The first die-casting machine got patented in 1849 for being hand-operated. The two forms of die-casting machines are hot-chamber die-casting and cold-chamber die-casting.

The hot-chambers are known as ‘gooseneck’ machines in which the piston got retracted and used to fill the gooseneck with molten metal. Lot of advantages can be listed for hot-chamber casting machines such as short cycle-times and easy conversion of metal into castings within the die machine. But, at the same time the die-casting machine exporters need to make the buyers aware that aluminium cannot be used in this machine because due to its affinity towards iron, it picks up some iron from that surface that blends into it, when in molten form. Hence, these are mainly used in tin, zinc and lead-based alloys.

At the same time, in the cold-chamber machine, the molten metal enters an unheated chamber that pushes the metal into the die with the help of the hydraulic machine. Due to this long process, the cold chamber machine has a longer cycle time.

However, the buyers can chose any of them as per their applicability. But there is another factor over which the quality of die-casting depends and that is, its set-up. It is constituted with two dies – Cover die half and Ejector die half. They meet each other on parting lines.

The cover-die should be attached to the stationary platen whereas the ejector-die is on the movable platen covering the path from the sprue (hot-chamber machine) or shot hole(cold-chamber machine) to the mold cavity that has two cavity inserts that has two separate pieces which can be easily separated and bolt into the die halves.

For an effective die-casting, the ejector die half needs to accomodate the material and should ensure that the ejector pins push the casting out when the die gets opened. To accomplish this task, all ejector pins need to move together at the same time through the ejector pin plate. Cores and slides are other components that need to be taken care of.

The materialistic properties, which the buyers of these die-casting machines will look at, in the dies are thermal shock resistance and softening at elevated temperatures. Also, the demand for such machines will get influenced by the hardenability, machinability, heat resistance, weldability and most importantly cost.

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