Isostatic pressing is to put pressure sample in high pressure vessel, using the properties of incompressible medium and uniform pressure transfer properties of uniform pressure on samples from all directions when the medium pressure vessel through the pressure pump, according to the principle of fluid mechanics, transmitted to each direction of the same size and uniform pressure.At this point, the pressure from all directions in the pressure vessel is uniform.

Features: when in the isostatic pressing, the pressure transmitted by the medium is equal in all directions. When the elastic die deformed under the pressure of the medium transferred to the powder in the mould, the friction between the powder and the die wall is small, the force of the compaction is uniform, the density distribution is uniform, The performance of the product is greatly improved. According to the forming temperature, isostatic pressing technology is usually divided into isostatic cold pressing (cold, isostatic, pressing, CIP), isostatic warm pressing (warm, isostatic, pressing, WIP) and isostatic hot pressing (hot, isostatic, pressing)

1. Isostatic cold pressing
The isostatic pressing is called cold isostatic pressing at room temperature. The process is as follows:
Powder-bagging-air exhaust-seal-isostatic pressing-pressure relief-decap and sampling-blank processing-sintering

Cold isostatic pressing is divided into two kinds:dry bag isostatic pressing and wet bag isostatic pressing.The dry bag isostatic pressing is to permanently fix the forming die (sleeve) in the high-pressure cylinder, and the powder is directly pressed into the sleeve in the high-pressure cylinder to be pressed.The utility model has the advantages that the utility model is suitable for mass production of simple shapes and parts, and is convenient for automation.

The bag used for wet isostatic pressing is not a fixed part of the high-pressure cylinder, and the cover is completely immersed in the liquid medium. The utility model has the advantages of strong adaptability, multiple bags at one time, small batch production, and large and complex parts.

2.Isostatic warm pressing
When the powder does not form at room temperature, warm isostatic pressing can be used. A binder with a high plasticizing capacity is usually added to the powder to obtain a higher strength of compacts by warm isostatic pressing, the feature is operating temperature between isostatic cold pressing and isostatic hot pressing.

3.Isostatic hot pressing.
Hot isostatic pressing is a kind of technology that makes the material endure isostatic pressing at high temperature (above 1000 DEG C) and high pressure (above 100MPa). The feature is that powder forming and sintering can combined together, and the utility model can also be used for diffusion bonding, defect elimination and other fields. The working medium usually uses inert gas (argon or nitrogen), and liquid metal and solid particles can also be used as pressure transfer medium. Sheathing materials are usually be metal or glass.

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Types of Isostatic Pressing