Binder removal thermal debinding

Binder removal can be accomplished by thermal decomposition or by dissolutiion. In ceramics, the thermal decomposition method is commonly used and will be considered here. The process is referred to as thermal debinding or, more simply, as binder burnout. In thermal debinding of ceramic green bodies, both chemical and physical factors are important. Chemically, composition of the binder determines the decomposition temperature and the decomposition products. Physically, the removal of the binder is controlled by heat transfer into the body and mass transport of the decomposition products out of the body. 

During thermal debinding, the feedstocks are heated until the binder is removed via thermal decomposition. Hence, it is important to study the thermal decomposition of the binder in the presence of the powder. The TGA (thermogravimetric analysis) is usually used for this study. The samples would be heated at programmed heating rate with a stream of nitrogen gas purging the furnace s interior to reduce oxidation of the metal powder in the feedstocks. 

Debinding is carried out in furnaces suitable for the binder system. The binder may be removed by way of catalysis, dissolving or thermal decomposition. Debinding ean be effectively achieved by a suitable furnace temperature and atmosphere. Removing the binder transforms the moulded part into a porous and sensitive moulded body, referred to as a brown compact . In this condition, the part is only kept stable by minimum binder residues and weak van der Waals forees. 

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