Influence of the Steel Powder Type and Processing Parameters on the Debinding of PM Compacts with Gelatin Binder

Artikel i vetenskaplig tidskrift, 2014

Binders present an important part of the powder metallurgy technology as they are vital to provide efficient powder agglomeration and/or lubrication during shaping. At the same time, they have to be easily removed from the compacts during initial stages of sintering without any harmful effect for the base material, as well as for the environment. Therefore, behavior of gelatin as a binder for stainless- and tool-steel gas-atomised powder compacts was studied by thermal analysis and electron microscopy. Thermal analysis showed that peak mass-loss occurred in the range between 340 and 370 C, depending on the base powder and heating rate. Risk for base powder oxidation at temperatures below 425 C was detected. Based on the obtained results, it is recommended to perform debinding at *425 C after applying a heating rate of around 7.5 C min-1. Only in this way efficient enough binder removal can be obtained concurrently to avoiding base powder oxidation.