Hot isostatic pressing is a process in which a component’s overall density is increased by removing excess liquids and voids. This normally occurs during a two-part process to ensure that the material is structurally-sound and able to withstand tremendous amounts of force while under stress. The component, usually a powder, is first exposed to extreme temperatures to eliminate moisture, and a heavy vacuum is also implemented to remove any impurities that it may contain. While this is taking place, inert gasses are introduced into the contained environment until the internal pressure creates a uniform metallurgical bond within the grain-sized particles. A hot isostatic pressing process results is metallic sand with density very close to 100%, which is ready to be shaped in almost any form for various industries.
One of the most popular examples of hot isostatic pressing is the process of cladding. By infusing a durable, rare metal or metallic powder across the exterior of a much more common material, manufacturers are able to produce cost-effective items that have an extended life expectancy since they are much more durable. While this was somewhat obtainable in the past by combining two different metals through metallurgy, hot isostatic pressing does not combine two metals in order to create an alloy. This allows the process to be applied to many different types of materials that were previously impossible, such as metallic casings on ceramic or plastic.
One of the major benefits of hot isostatic pressing for many industries is the large reduction in the amount of wasted components, which saves manufacturers as much as 30% off of their material purchases and labor. Prior conventional methods resulted in a large amount of scrap metal being left over during the final phases of construction, and since rare materials like tungsten carbide were very expensive, this was a serious problem. Since this process can replicate very complex geometrical shapes at almost any scale, very little metal is lost during the final shaping process.
The first implementations of the hot isostatic pressing process can be dated back to 1955, with the goal of making complex, uniform materials that could not otherwise be achieved through bonding or welding. While this technology was originally created for servicing the aerospace industry to protect against the external pressure that is placed on spacecrafts, it quickly became popular within the oil, automotive, and medical industries as well. Even rocket engines and deep space satellites are have been constructed using this process, because there is simply no other way to make them with greater durability. Since the volume of shapes and sizes that can be created are almost limitless, hot isostatic pressing should continue to remain a popular alternative in many separate industries.