Introduction to the Process of Investment Casting

Investment casting is a familiar forging process for foundries. One process of silica sol precision casting process is mainly divided into five processes: wax pressing, shell making, pouring, post-treatment process and detection. The wax pressing process includes wax pressing, wax replenishing and tree fixing; Shell making includes three steps: sanding, sizing and drying; Post treatment process includes sand blasting, rectification, pickling and passivation. The inspection includes wax inspection, re inspection, intermediate inspection and quality inspection.

Investment casting may be a little unfamiliar to some small partners who do not understand forging, but it is a relatively familiar process for silica sol precision casting manufacturers. Since foundry manufacturers usually do this process, what should we pay attention to in the forging process? Now I will sort out the confirmation methods of pressure holding, mold filling time and mold release in investment casting. I hope these methods will help consumers who want to know about investment casting.

1、 After pressure holding, the casting shall be removed from the mold, so the time from the completion of injection to the die casting mold is called the die casting time. The high precision casting can have a certain compressive strength in the abrasives in sufficient time. If the opening time is inconsistent with the popping time, the product will be deformed and cracked. If the opening time is short, the casting will be out of the mold when the compressive strength is low, which will also cause the casting deformation.

2、 In the aluminum die casting process, shape memory alloy enters the die casting cavity and fills the female die. The time required during this period is called recharging time. The filling time depends on the dimensional diversity of the casting. Generally, the filling time of simple castings is fast.

3、 The duration of thermal insulation depends on the color and thickness of high precision castings. If it is a casting with high melting point, wide crystallization temperature range and thickness, the holding time will be longer; If it is a casting with small crystal scope and wall thickness, the heat preservation time will be shorter; During pressure holding, silica sol precision casting manufacturers should also reduce the pressure holding time. If the heat insulation and heat preservation time is not enough, it is easy to cause shrinkage porosity of castings. However, if the pressure holding time is too long, it will not play a very important role. Conversely, it will make it difficult to disconnect the leftover materials at the corners of the vertical aluminum die-casting machine. Therefore, operating the pressure holding time is also a key link.