Powder injection Molding(PM) This is the same as the PM process(section 16.4.2), except that the powders are ceramic rather than metallic, Ceramic partices are mixed with thermoplastic polymer, which acts as a camer and provides the proper flow characteristics at molding temperatures. The mix is then heated and injected into a mold cavity. Upon cooling, which hardens the polymer, the mold is opened and the part is removed. Because the temperatures needed to plasticize the carrier are much lower than those required for sintering the ceramic, the piece is green after molding. Before sintering, the plastic binder must be removed. This is called debinding, which is usually accomplished by a combination of thermal and solvent treatments. Applications of ceramic PIM are currently inhibited by difficulties in debinding and sintering. Burning off the polymer is relatively slow, and its removal significantly weakens the green strength of the molded part. Warping and cracking often oceur dunng sintering. Further ceramic products made by powder-injection molding are especially vulnerable to microstructural flaws which limit their strength.