Types and principles of isostatic presses

Isostatic Pressing Types and Principles: It is a forming method that takes advantage of the incompressibility and uniform pressure transfer of liquid medium, that is, the pressure of the specimen in the high-pressure container is the same as the pressure of the liquid medium at the same depth. Types of isostatic pressing Types Isostatic pressing techniques can generally be divided into three types according to the temperature during forming and consolidation: cold isostatic pressing (CIP), warm isostatic pressing (WIP) and hot isostatic pressing (HIP).

2023-04-21 08:55:51Sichuan Lineng Ultra-High Voltage Equipment Co., Ltd511

Isostatic pressing principle Isostatic pressing is also called hydrostatic pressing. It is a forming method that takes advantage of the incompressibility and uniform pressure transfer of liquid medium, that is, the pressure of the specimen in the high-pressure container is the same as the pressure of the liquid medium at the same depth, so it is called hydrostatic pressure or isostatic pressure. The molding process obtained according to this principle is called hydrostatic forming, or isostatic forming.

(1) Isostatic pressing type Isostatic pressing technology can generally be divided into three types according to its temperature during forming and consolidation: cold isostatic pressing (CIP), warm isostatic pressing (WIP) and hot isostatic pressing (HIP). Due to the difference in temperature during isostatic pressing, the three isostatic pressing technologies use corresponding equipment, pressure medium and cladding mold materials.具体根据客户产品要求进行设计定制。

Cold isostatic pressing is divided into two types: wet bag method and dry bag method. The wet bag method isostatic pressing is to put the powder into the forming mold (i.e., the wrap) first, seal it, and then put it in a high-pressure cylinder for pressing. During pressing, the sleeve is completely immersed in liquid and is in direct contact with the pressure transfer medium. The wet bag method has strong applicability to isostatic pressure, especially suitable for experimental research and small-batch production, and can press more than two different shapes of parts and produce large and complex shapes in a high-pressure cylinder at the same time, with a short production process and low cost.The dry bag method is isostatic pressing, and the pressurized rubber mold is put into the cylinder in advance, and it does not dare to come out when working. After the powder is loaded into the forming rubber mold, it is put into the pressurized rubber mold together, or the powder is sent to the pressurized rubber mold through the feeding hopper from above. This method can achieve continuous operation, open the upper lid, load from the hopper, then cover the upper lid and press molding. When the blank is taken out, open the upper cover and push the blank out from above through the top rod at the bottom. The dry bag method has a high degree of automatism and a short operation cycle, making it suitable for mass production, but the size and shape of the formed product are limited due to the fact that the pressurized rubber mold is not easy to replace frequently.

When the powder is difficult to form at room temperature. Optional thermostatic pressure. Thermal isostatic pressure is generally carried out at temperatures of 80 - 200 °C, and some are carried out at 250 °C or even 450 °C. At normal temperature (80-120°C), oil is used as the pressure transfer medium. The medium can be heated in the oil supply tank, and when precise temperature control is required, it can also be heated with a heating element in the high-pressure cylinder, and can be heated and cooled according to the process requirements. The general pressure used by warm isostatic pressing is about 300MPa, and the equipment used is roughly the same as that of the wet bag isostatic press.

Hot isostatic pressing refers to the process of subjecting materials to isostatic pressure under the simultaneous action of high temperature and high pressure. Usually inert gases (such as argon, nitrogen, ammonia, etc.) are used as the pressure transfer medium, and liquid metal or solid particles can also be used as the transfer medium for hot isostatic pressure. The sleeve used to encapsulate the material to be pressed is commonly prepared of metal or glass.