Abstract
Carbonyl nickel sintered compacts were observed with an acoustic microscope. The specimens were compacted under pressure of 98-98OMPa, and were sintered at 1073K for 3.6ks in hydrogen atmosphere. The results were as follows.
1)In the case where compacting pressure was more than 490MPa, pores were almost closed.
2)When pores were almost open, peaks of V(z) curve did not appeared. According to increase of closed pores, however, these begun to be shown at defocus value of-17μm and-30μm.
3)In the case of comparison of optical and acoustic images, pores which can not appeared clearly on specimens surface by the former were emerged as characteristic images by the latter.
Therefore, as results of observation of surface and subsurface pores in acoustic microscopy, this technique suggests interesting and unique information different from optical images for distribution and connection of pores in fine powder sintered compacts.
