Abstract
In fluence of cold rolling and annealing on the damping capacity of Fe sintered compacts, infiltrated with Pb was investigated by measuring internal friction. Infiltration volume ratio of Pb in sintered Fe compacts and draft of the specimens were up to 31.6% and 40%, respectively, and annealing temperatures were mainly 473 K. Results obtained were as follows:
(1) Internal friction of Fe sintered compacts, infiltrated with Pb increased with the increase of infiltration volume ratio of Pb. Work of cold rolling enhanced the internal friction of specimens remarkably, but in the case of low volume ratio of infiltrated Pb in Fe sintered compacts, the internal friction tended to saturate at a certain draft.
(2) Ultimate tensile strength of the specimens increased with the increase of draft, showed a maximum value, and then decreased with the increase of draft. Maximum value of ultimate tensile strength of the specimen tend-ed to shift to higher draft with the increase of Pb infiltration volume ratio.
(3) Internal friction of cold rolled Fe sintered compacts fell down to that before cold rolling with annealing time at 473 K. On the contrary, in the case of cold rolled Fe sintered compacts, infiltrated with Pb, higher inter-nal friction was retained to prolonged annealing time. The origin of decrease of internal friction by annealing is thought to be the recovery of internal stress in Fe matrix by cold rolling.
(4) Internal friction of Fe sintered compact, infiltrated with 30 vol%Pb and cold rolled at 40% of draft was approximately the same as that of flaky graphite cast iron. Whereas, ultimate tensile strength of this specimen was comparatively lower value of approximately 13 kgf/mm2.
