Abstract:The relation between the tempering effects of sinterd SmCos alloy at 750℃and its intrinsic coercivity (i^HC) has been studied by the use of photoelectron energy spectrum, X-ray diffraction and high-voltage electrop microscope. The result is that the cause of i^HC dropping seriously for sintered SmCo₅ alloy tempered at 750℃ is not the eutectoid decomposition of SmCo₅ and the increase of oxygen. In fact, i^HC dropping is caused by that some defect-rich regions in Sm₂Co₁₇ decomposed form SmC0₅ from nucleation centers in reversed magnetization course.

Key words: sintered alloy, tempering effect, intrinsic coercivity, SmCo₅