Author Description

This paper shows the effect of cold-working on the mechanical properties of a series of eight phosphor bronze alloys in the form of cold-rolled strip. The tin content of these alloys varied from 0.5 to 10 per cent. Each material was furnished in two conditions with different ready-to-finish grain sizes. Electrolytic tough pitch copper strip similarly treated is included to provide a base for evaluating the effectiveness of the tin additions. The mechanical propertiesincluding tensile strength, proportional limit, yield strength at both 0.01 and 0.2 per cent offset, modulus of elasticity, elongation, bending fatigue characteristics at lifetimes ranging from 100,000 to 100,000,000 cycles, and the Rockwell hardness (B and 30T values)are reported for six different tempers of each of the 18 materials. The tempers studied include annealed, half-hard, hard, extra-hard, spring and extra-spring. Data are also included on the 3, the 4, and the 5 per cent tin alloys to show the effect of a higher phosphorus content. The effect of a larger ready-to-finish grain size on the mechanical properties of the high phosphorus, 4 per cent tin alloy is discussed.