If you need to post process parts in order to achieve the desired properties by heat treatment or cleaning, Air Liquide offers the right solutions based on technical gases.
Nitrogen, Argon and More for Heat Treatment in Additive Manufacturing
Especially parts manufactured in powder bed processes such as SLM, DMLS or EBM are characterized by high internal stress due to the extremly rapid cooling of the molten metal. Stress relieving is typically carried out on these metal products in order to minimize residual stress in the microstructure and achieve better mechanical properties. Simply speaking this means heating the part up to a specified temperature, holding it at that temperature, and then cooling the part at a relatively slow rate. At the elevated temperatures – typically between 550°C and 650°C for steel – the parts need to be treated under an inert atmosphere or under vacuum. Like any manufacturing step, if not performed properly this simple operation can have disastrous consequences such as oxidation, dimensional changes or inferior mechanical properties. One of the most critical parameters in the process is the atmosphere in the heat treatment furnace.
In order to achieve the desired process atmosphere Air Liquide offers specific gas supply solutions and related equipment for heat treatment. By working with our heat treatment experts you will save time and money. They understand your needs and will help you translate your specific heat treatment to the optimal gas supply solution for the reliable supply of high quality nitrogen, hydrogen and hydrocarbons.
High Pressure Gas Supply for Hot Isostatic Pressing (HIP)
In critical applications with demanding mechanical requirements the microporosity of additively manufactured parts needs to be eliminated. This can be achieved by hot isostatic pressing (HIP). HIP is a form of heat treatment that uses high pressure at elevated temperatures to improve material properties. The combination of extremely high pressure (up to 3000 bars) with heat eliminates internal porosity through a combination of plastic deformation, creep and diffusion. An inert gas atmosphere, typically argon, is required to avoid any chemical reaction with the base material. The gas supply solutions for hot isostatic pressing are very demanding due to the high pressure and batch operation mode. Air Liquide has developed tailor made gas supply solutions that are cost-competitive and help to reduce capital expenditure. With an extensive network of air separation units across Europe large quantities of argon can be reliably supplied.
Cleaning with Dry Ice and CO2 Snow
The perfect finish requires high-end surface cleaning. Use carbon dioxide based cleaning processes to remove powder residues and other particles from your parts. Cleaning with dry ice or CO2 snow is an environmentally friendly and cost-efficient process that provides optimal results.