Thin cylinder hardness testing method - being produced by knife edge of standard material pressed into and then retracted to produce response curves

摘要

A narrow cylindrical body, esp. a wire or needle of 0.5-5.0 mm dia. is laid in the prismatic groove (22) in a support (21) and then inserted by applying vertical pressure to a transverse knife-edge (24a), esp. of diamond. As the knife edge penetrates, the increasing depth is recorded in relation to applied force and recorded in a computer. From a certain depth, the knife-edge is then retracted via the same path. The distance between the two graphical curves, for loading and relaxation and/or the different slopes in selected areas of the two curves determine the hardness of the specimen relative to the knife-edge material. The process may be repeated at least once and penetration may be linear or circular. ADVANTAGE - Hardness is quickly and automatically tested for cylindrical body, without previous need for embedding and surface grinding.