The principle of a low-pressure die-casting machine

Permanent mould coatings are typically formulated using water as a carrier, a high temperature binder (normally sodium silicate) and a refractory filler or blend of fillers. There are two categories of coatings  

Coatings are generally sprayed onto the die. Careful attention to die preparation, coating preparation and application and the t5q)e of coating equipment utilised can yield significant quality and productivity benefits. 

Hot-chamber HPDC machines comprise a molten metal reservoir, the die, and a metaltransferring device, which automatically withdraws molten metal from the reservoir and forces it under pressure into the die. A steel piston and a cylinder system with a gooseneck is used to create the necessary pressure within the die. A gooseneck machine utilises a cast iron channel to transfer the molten metal from the reservoir to the die. Pressures can range from a few bar to over 350 bar. Hot-chamber techniques are mainly used for zinc alloys and magnesium alloys. 

This technique is used to produce cylindrical products in cast iron, steel, and in alloys of aluminium, copper and nickel. T5q)ical parts made by this process are pipes, boilers, pressure vessels, flywheels, cylinder liners and other parts that are axis5mmetric. 

---

Figure 2.44 The principle of a low-pressure die-casting machine [175, Brown, 1999]...

---