Casting Technology: Complete Collection of Graphic Casting Process(3)
(7) vacuum die casting (vacuum die casting)
Vacuum casting: An advanced die-casting process that improves the mechanical properties and surface quality of die-casting parts by removing or removing the pores and dissolved gases in the die-casting part by removing the gas in the cavity of the die-casting mold during the die-casting process.
1. Eliminate or reduce the pores inside the die-casting parts, improve the mechanical properties and surface quality of the die-casting parts, and improve the plating performance;
2. Reduce the back pressure of the cavity, use lower specific pressure and alloy with poor casting performance, it is possible to die cast large castings with small machine;
3. Improved filling conditions, which can die-cast thinner castings;
1. The mold sealing structure is complicated, and the manufacturing and installation are difficult, so the cost is high;
2. If the vacuum die casting method is not properly controlled, the effect is not very significant.
(8) Squeezing die casting
Squeeze casting: A method in which a liquid or semi-solid metal is solidified and flow-formed under high pressure to directly obtain a part or a blank. It has the advantages of high utilization rate of liquid metal, simplified process and stable quality. It is an energy-saving metal forming technology with potential application prospects.
Direct extrusion casting: spray coating, alloy casting, mold clamping, pressurization, pressure holding, pressure relief, parting, blank demoulding, resetting;
Indirect extrusion casting: spray coating, mold clamping, feeding, filling, pressing, holding pressure, pressure relief, parting, blank demoulding, resetting.
1. It can eliminate defects such as internal pores, shrinkage holes and shrinkage;
2. Low surface roughness and high dimensional accuracy;
3, can prevent the occurrence of casting cracks;
4. It is easy to realize mechanization and automation.
Application: Can be used to produce various types of alloys, such as aluminum alloy, zinc alloy, copper alloy, ductile iron, etc.
(9) Lost foam casting
Lost Foam Casting (also known as solid casting): It is a combination of paraffin or foam model similar in shape and shape of casting into a model cluster. After brushing and coating the refractory paint, it is buried in the dry quartz sand and vibrated. The new casting method of casting is carried out by pressing down the casting to vaporize the model, occupying the position of the liquid metal, and solidifying and cooling.
Process: pre-expansion→foaming molding→dipping coating→drying→styling→casting→falling sand→cleaning.