Temperature profile and sinterability of self-heating porous NiO-(Ce, Sm)O₂ composite during microwave irradiation

The microwave-assisted self-heating profile and sinterability of porous NiO-(Ce, Sm)O₂ composites with 25, 50 and 75 mass% NiO, which were prepared by heating at 800-1200°C for solid oxide fuel cell applications, were investigated. The porous NiO-(Ce, Sm)O₂ composites were heated to ea. 1300°C within 5 min in a microwave field. The sinterability of the self-heating NiO-(Ce, Sm)O₂ composites in a microwave field was dependent upon the mixing ratio of NiO and the pre-heating temperature. A large shrinkage of over 20% was achieved for the 25 mass% NiO-containing composites microwave-heated at 1300°C for 2 h after the pre-heating at 800°C. The sinterability was comparable to that by conventional sintering at 1400°C for 2 h.