Faster, cheaper, energy-efficient fabrication of strong permanent magnets

https://www.eurekalert.org/news-releases/1095333

"high temperature/ pressure (>100 MPa) sintering often results in uneven distribution of porosity throughout magnetic material with high porosity at the center/ rare earths very reactive to oxygen... new method uses friction stir consolidation: alloy powder placed in pressurized (<1MPa) chamber, stirred with rotating tool, powder sintered into solid eliminating porosity without melting alloy... frictional heating from particles rubbing together fuses powder without pockets/ bubbles forming, uniform throughout... less oxidation"