Key Issues of Hot Forging of Titanium Powder

Powder forging performance is attractive, the most important thing is that the dynamic performance is often better than most casting and forging products. Hot forging also has some problems. For example, although full density has been reached, inclusions can seriously damage the performance of powder forged products. Inclusions are caused by oxidation of the compact in the porous state, dirt entering the pores, and lubrication from the mold. Therefore, care should be taken to protect the cleanliness of the compact to prevent entry of inclusions.

For the hot forging process of titanium, powder sintering forging is often used at present. It is made by pressing titanium powder into a preform, then vacuum sintering to obtain a sintered body with a certain strength, and heating it to the forging temperature. After heat preservation, it is quickly moved to the hot forging die cavity for forging, forging to meet the design size Forging. At the same time, it can obtain a uniform fine-grained structure, significantly improving the strength and toughness of titanium products. The design and manufacture of preforms are also one of the key issues in hot forging.
Powder sintered forged Chin alloy is suitable for the manufacture of various high-temperature aircraft engine parts, such as propellers, compressor disks, blades and impellers. Titanium alloys have higher alloy element content, severe segregation of casting blanks, poor plasticity, and difficulty in forging. Using powder sintering and forging process can overcome the above deficiencies.

For example, a hot forging process is used to produce an aircraft compressor disc. First, the PA milled alloy powder is hot isostatically pressed to obtain a preformed blank with a theoretical density of 99.3%, and then the blank is hot forged. The hot forging process controls the temperature to reach 900-1040℃, mold preheating temperature reaches 370℃, strain rate 0.1/s, unit pressure is 360 MPa.

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