Extrusion of Metal–Ceramic Composite Pipes


  • F. W. Zok—contributing editor


Metal–ceramic composite pipes were prepared through simultaneous extrusion of different pastes by a multi-billet extrusion method. ZrO2 and stainless steel powders were chosen, and an aqueous solution of water-soluble polymer, hydroxypropyl methylcellulose (HPMC), was used as binder. The maximum extrusion pressure and the minimum amount of binder required reached their lowest values when the mixing fraction of ZrO2 powder was 0.4. The minimum amount of binder for forming the outer layers was 4%–5% higher than that for inner layers, even for the same powder. It was possible to decrease the binder content and broaden the extrudable range of the binder content by means of mixing coarse and fine powders.