圧延を施した焼結鉄ならびに鉛溶浸焼結鉄の内部摩擦について

Abstract

For the purpose of estimating the damping capacity of composite structure type lead infiltrated iron compacts, the internal friction of them and of Fe sintered compacts for a comparison were measured, and influences of cold rolling and annealing on the internal friction were also studied. Results obtained were as follows:(1) The internal friction of Fe sintered compacts increased with an increase of porosity of compacts up to about 26%. Beyond that, the internal friction was retained almost constant value regardless of an increase of porosity of compacts. The internal friction of Fe sintered compacts could be enhanced remarkably by the rolling. But the enhanced internal friction was thermally unstable, and was reduced to the level of assintered condition after a short-time annealing.(2) The internal friction of Pb infiltrated Fe sintered compacts also increased with increasing both the Pb infiltration ratio and the rolling reduction. The internal friction of this material was thermally stable, i.e. the reduction ratio of internal friction was approximately one fifth after a prolonged annealing time. The damping mechanism of this material is thought to be mainly due to the absorption of vibration energy by the external friction at the interface between Fe skeleton and Pb infiltrant.