The material usually shrinks significantly, and often the sintering process occurs in a die with a compaction pressure. The vacuum in space generally helps this process.
Microwave heating allows quicker uniform heating.
The result is a fairly low density material which can be cut and shaped fairly easily, can hold small loads in compression, and provides good thermal insulation, but cannot take much stress in tension and is brittle. Sintering allows production of parts without melting and liquid casting processes, i.e., dealing with only powder or fine sand. Desai et al. Battelle produced a report for Lockheed on a lunar sintered regolith production facility which was very well received by the community. The NASA Johnson Space Center has a technical paper on-line on sintering .