切りくず形態の金属物理的考察

抄録

The study appears from the going discussing that the metal physical properties of the chip may allow a deeper insight into the morphology of the chip produced by use of dislocation theory. An experimental investigation has been carried out with the aim to analyze, in some detail, the general facts under which the chip tensile strength and hardness change occur. And it describes to fundamental relation of the micro- and macro-chip formation mechanisms on polycrystalline aluminium of high purity (99.78 and 99.998 percent aluminium). The main results obtained are summarized as follows.
(1) The tensile strength σ_B of the chip increases from 2 to 6 times value of the bulk. The fact is investigated by the dimension of the very small magnitude dimple pattern in the fracture surface.
(2) The lamellae of the chips are always generated perpendicular slip direction <111> to chip flow direction in micro- and macro-chip formations. And the minimum lamella slip spacing was the order of 100-150 atomic planes spacing.
(3) The shear stress τ_av of the macro-chip formation process developed by Zwolkin-Piispanen-Merchant is in good agreement with value calculated of the average shear stress for polycrystalline aluminiums using a dislocation theory in the micro-chip formation.