The continuous development and progress of modern technology promotes the development of materials in the direction of high efficiency and high performance, and the development and progress in the field of high-temperature structural materials is particularly obvious. Titanium alloys have attracted more and more attention from scholars due to their low density, high specific strength, good creep resistance and corrosion resistance.

The raw material cost of titanium alloy is high. The traditional processing methods of casting and forging are complicated and the material utilization rate is only 30%. Castings are prone to defects such as pores, inclusions and element segregation, and are prone to oxidation during the processing and preparation process. These defects seriously restrict the mechanical properties and usage conditions of titanium alloy components, and limit the expansion and development of industrial applications of titanium alloys.

Compared with traditional titanium alloy casting and forging manufacturing processes, hot isostatic powder metallurgy has the following advantages:

(1) The product has high density, good uniformity, and excellent comprehensive mechanical properties, which are equivalent to forged components;

(2) The component structure has wide adaptability, and the combination of cladding and core can meet the overall forming needs of complex-shaped products, with high surface quality and low machining volume.

(3) The material utilization rate is improved, compared with traditional casting and forging processes. The material utilization rate of hot isostatic powder metallurgy technology exceeds 50%, the process method is simple, and the production cycle is short.

The main steps of hot isostatic pressing powder metallurgy technology include:

1. Make powder and design and make sleeves and cores according to the size of the formed parts;

2. After detecting leakage in the bag, fill the metal powder into the bag and compact it;

3. Sealing and welding the package after vacuum degassing.

After hot isostatic pressing, the cladding is removed by machining or acid etching, and finally the finished parts are obtained by local finishing. By selecting high-performance titanium alloy powder and subjecting it to strict production process control, the mechanical properties of the final hot isostatically pressed powder metallurgy titanium alloy component are close to or partially better than that of forged titanium alloy. The excellent mechanical properties are due to the high density and good uniformity of the parts under high temperature and homogeneous pressure. On the other hand, because the sintering temperature is below the β phase transformation point, the fine structure formed by rapid solidification during the preparation of titanium alloy powder can be fully retained, making the final material grains fine and uniform.

The quality of titanium alloy powder determines the mechanical properties of powder metallurgy hot isostatic pressed components. The shape, size, and fluidity of titanium alloy powder prepared in different ways are different, which greatly affects the quality of powder metallurgy near-net shape products.

The gas atomization method causes the molten metal to be crushed into small droplets by high-speed airflow in the atomization chamber, and finally cooled into metal powder, as shown. According to the different ways of forming metal droplets, it can be divided into vacuum induction melting gas atomization (VIGA), electrode induction melting gas atomization (EIGA), and plasma atomization (PA).

Plasma rotating electrode atomization method (PREP) is the most widely used method among centrifugal atomization methods. The principle is to rotate a round rod-shaped titanium alloy electrode at high speed and use the high temperature generated by discharge plasma to atomize one end of the electrode. Melting, the molten alloy is thrown out of the electrode end surface at high speed under the action of centrifugal force, and the alloy droplets are further crushed by high-purity inert gas in the atomization chamber, and rapidly cooled to form powder.

Gas atomization method and plasma rotating electrode atomization method are currently the most important methods for preparing pre-alloyed powder of titanium and titanium alloys. They are mainly used in high-end fields such as aerospace and aerospace, while lower-cost elements are used in ordinary automobile or civilian fields. Titanium powder prepared by mixing method or hydrodehydrogenation method.

During the hot isostatic pressing process, the temperature and pressure experienced by the package are isotropic, and the actual shrinkage rate of the package is greater than 30%, and the powder material is affected by process parameters, material properties and part structure, resulting in uneven shrinkage of the parts. The shape undergoes major changes.

Therefore, we should master the changing rules of the powder densification process, combine the functions of three-dimensional modeling software and finite element simulation software through computer technology, study the shrinkage rules of key dimensions, assist in the design and prediction of key dimensions of the package, and combine package design, titanium The combination of the densification process in alloy HIP and the simulation of powder metallurgy products has great significance in saving costs, improving work efficiency, and providing strong support for the preparation of various engineering components by the HIP process.