Manufacturing companies use a variety of techniques to alter and improve the properties of raw materials. Some of these techniques are basic, consisting of nothing more than exposure to heat, whereas others are more complex. Hot isostatic pressing (HIP) falls under the latter category of treatment processes. Unless you’re familiar with HIP, though, you might be wondering how it works.
What Is HIP?
HIP is a material treatment process that involves the use of heat and pressure to improve the physical properties of a material. It’s typically performed on metals and ceramics. When either of these types of materials are exposed to heat and pressure, their physical properties change.
With HIP, the material is placed inside an HIP machine. HIP machines feature both a furnace and pressure vessel that changes the physical properties of the material. Argon gas is forced inside the HIP machine, thereby increasing the vessel’s temperature as well as pressurizing the vessel. After allowing the argon gas to sit for a specific amount of time, the vessel is cooled. When finished, the treated material is removed from the vessel.
Benefits of HIP
HIP offers many benefits when compared to other material treatment processes. For starters, it allows manufacturers to create stronger and more durable products. When certain materials, such as metals and ceramics, are exposed to heat and pressure, they become stronger and more durable.
Some manufacturing companies use HIP to minimize the production of scrap material. By treating the material with pressure and heat beforehand, the material will typically create less scrap when used in other manufacturing processes.
Metal powders can be converted into solid material using HIP. For this type of HIP process, however, more pressure is required. It’s not uncommon for metal powders to be exposed to up to 15,000 pounds per square inch (PSI) of pressure. Combined with heat, the pressure squeezes the metal powders together, resulting in the formation of a solid material.
HIP vs Cold Isostatic Pressing (CIP): What’s the Difference?
Cold isostatic pressing (CIP) is similar to HIP in that both material treatment processes use pressure to improve the physical properties of a material. As the name suggests, however, CIP is performed at lower temperatures than its HIP counterpart. According to the European Powder Metallurgy Association (EPMA), HIP is typically performed at roughly 1,650 to 2,300 degrees Fahrenheit. In comparison, CIP is performed at or near room temperature. CIP is a faster and easier material treatment process, but it doesn’t offer the same benefits as HIP.