Hot Isostatic Pressing (HIP) is to place the product in a closed container, apply equal pressure in all directions to the product, and apply high temperature at the same time, under the action of high temperature and high pressure, the product can be sintered and densified. It has become a practical technology in the production of many high-performance materials today, and it is also an indispensable new technology for the development of new materials.
In the process of processing, we want to obtain a uniform and refined structure, reduce material loss, reduce subsequent machining and other processes, hot isostatic pressing products, excellent performance, short production cycle, wide range of applications, more and more powder metallurgy products using hot isostatic pressing process for forming and densification, such as powder metallurgy high-speed steel, stainless steel, powder metallurgy superalloy, aircraft engine turbine disk, etc., especially in aerospace, energy and power, tool and die materials, electronic semiconductors, automobiles, medical fields to be used at high frequency.
Hot isostatic pressing is often used in the range of high internal requirements for materials, not easy to repair or integrally molding, after hot isostatic pressing equipment is becoming more and more intelligent, automated, large-scale, hot isostatic pressing technology is becoming more and more advanced, and compared with before, it has become a relatively simple and efficient near-net shape densification technology, because the hot isostatic pressing method applies equal static pressure molding in all directions to the workpiece at high temperature, making it compare with the traditional process with the following advantages:
(1) It can be compressed to form a workpiece with a complex shape
(2) The workpiece that has been subjected to HIP has a consistent density
(3) The high gas density can promote heat exchange, increase the heating speed, and shorten the cycle time
(4) Brittle materials can also be compression-molded due to very consistent heating
For the above advantages of HIP can be reflected in the product as follows:
1. Uniform strength
With HIP pressing, the material has uniform strength in all directions. This is because the pressure used in the process is applied evenly in all directions of the material.
2. Improved mechanical properties
Materials subjected to HIP treatment have improved mechanical properties. These properties include ductility and strength. The improvement in mechanical properties can be attributed to the fact that most defects in the material are eliminated in the HIP process.
3. Enhanced corrosion resistance
HIP improves corrosion resistance, which ensures that HIP materials have a longer service life than most other materials.
4. Cost-effective
HIP 是一种极具成本效益的工艺。通过这个过程，在质量保证测试上花费的钱更少。这是因为经过热等静压处理的材料质量很高。此外，该工艺延长了固体材料的使用寿命，这意味着该材料在更换之前可以使用很长时间。
5. Microstructure
The microstructure of materials subjected to HIP is greatly improved. The microstructure of these materials is homogeneous. In addition, the particles are fine and not separated. The density of HIP products is high, which is generally 5 ~ 15 higher than that of one-way and two-way compression molding. The relative density of HIP products can reach 99.8%~99.09%.
In the spacecraft manufacturing industry, HIP is mainly used to manufacture dense carbonaceous structural parts, such as the rudder surface of rockets and the throat lining of solid rocket engine nozzles. Precision castings of various alloys, such as high-temperature alloy turbine blades, cast titanium casings and aluminum alloy castings for turbochargers, etc., can be densified by HIP to eliminate internal porosity and shrinkage porosity, and improve performance, reliability and service life. HIP is also an effective way to rework old parts to extend the service life, for aerospace other aspects of casting performance has been widely concerned, with the continuous research and development and exploration of HIP technology, HIP technology is also extending to the civil field, the focus on HIP technology GE has been deeply cultivated in related fields for many years, and constantly tries to extend HIP technology in addition to the strong field of aerospace and extended to the daily 3C field and other aspects, Popularize hot isostatic pressing technology into daily life and apply it to create intelligent manufacturing of the whole industrial chain of hot isostatic pressing;
Doevol Materials is also committed to the continuous research and development, exploration and creation of new technology applications in the civil field using HI static pressing process, and has successfully realized the application of HI to the twin-screw granulation extrusion industry, the field of composite rolls and the homogenization range of lithium batteries, and continues to innovate and develop and strive to use HIP technology to bring more progress in materials and processes in other fields.
Although HIP has been popularized in many high-end industries and has also been applied in the civil field, HIP is not a “cure-all”, HIP has a good effect on the elimination of some materials and internal defects, but improper HIP process setting will also cause serious consequences, so the following matters should be paid attention to when using HIP:
(1) For open defects (defects that extend from the inside of the part to the surface of the part and communicate with the external gas medium), hot isostatic pressing does not play any role in eliminating the defect;
(2) When there is a large defect in the part (more than 2mm), a pit will be formed on the surface of the part, which needs to be repaired by welding. Pits can lead to part scrap when they appear in locations where weld repair is not possible, such as thin-walled parts, thin-walled parts, or blades.
(3) The elimination of internal cracks and inclusions is small;
(4) HIP may cause oxidation on the surface of the part, forming a thin oxide film, which is best carried out between finishing;
(5) HIP may cause serious deformation of parts, so precautionary measures to prevent deformation must be considered before HISTA;
(6) Improper setting of process temperature and pressure may cause the wall thickness of the parts to be thinned, and in serious cases, the grains of the parts will be seriously coarse, resulting in poor material properties and scrapping of parts;
(7) For alloys with large differences in the melting point of alloying elements, it may cause low melting point chemical element burning;
(8) It is not suitable for eutectic alloys, which are easy to form liquefaction cracks;
Doevol Materials has been deeply engaged in the research and development of hot isostatic pressing process for many years, and has accumulated rich accumulation in technology, experience, processing equipment, etc., and has built a leading technical team in the civil field in continuous exploration.
The physical industry has always been the foundation of scientific and technological development, and the material industry is an unavoidable topic in industrial development. The iteration and update of metal materials are a long and complex process, and Doevol Materials has found a cost-effective solution suitable for the civilian field through continuous experiments, data accumulation and integration, and failure experience summary in years of exploration.
Doevol Materials has always adhered to the corporate vision of “advanced materials make the world better”, and is also committed to becoming “the world’s leading solution provider of hot isostatic pressing materials and product solutions”, adding Doevol strength to the industrial power.