Bi系超電導圧粉体へのレーザ照射処理 : 第3報 : 表面溶融処理材の形態と機械的性質 Laser Treatment of Press Formed Superconductor Powder of Bi System : 3^<rd> Report : Morphology and Mechanical Properties of Surface Melted Bulk
The authors have reported that superconductive layer can be produced underneath the laser melted layer of press formed bulk of prospective superconductive powder of Bi system. This paper deals with the morphology and mechanical properties of the bulks, which were press formed at pressures between 29 MPa and 196 MPa and treated by laser scan with different powers such as 6, 7 and 8 W. Results showed that (1) the bulk forming pressures adopted in the study give negligible influence on the width of the groove the laser scanning caused while the laser scan results in the grooves with width from 2.3 to 3.4 mm, (2) the laser scan on the surface of the bulk produces groove with depth from 0.71 to 0.18 mm with the increasing power, (3) the resultant thickness of the melted layer is in the range between 600 and 900 μm, and that of the superconductive layer is in the range between 50 and 120 μm, (4) the bulk forming pressure affects surface roughness of the treated region in such a way that with increasing pressure the surface roughness increases in the value from 5.2 to 7.3 μm<I>R<SUB>a</SUB></I> although the laser output power gives small effects on the value, (5) the hardness measurement shows the highest value 120 Hv was obtained for the superconductive layer, 100 Hv for the melted layer and 45 Hv for the body as press formed, (6) the laser treatment causes the fracture strength to effectively change the value from 15 (before treatment) to 34 N (after treatment).
粉体および粉末冶金 54(2), 130-135, 2007-02-15
Japan Society of Powder and Powder Metallurgy