Question

It is necessary to select a metal alloy for an application that requires a yield strength of at least 310 MPa (45,000 psi) while maintaining a minimum ductility (%EL) of 27%. If the metal may be cold worked, decide which of the following are candidates: copper, brass, or a 1040 steel. Why?

Answer 1

ANSWER

Given data

the required at least yield strength of the metal alloy = 310mpa

minimum ductility maintained (%EL) = 27%
Consider the mininum cold work ( needed to reach the Yield strength and the maximum possible cold wook for the ductility in selection of metal alloy for the application, from the graph of figure 7119 a (plot better on increase in yield strength and percent cold work). note the minimum cold work needed at oq foy Steel, brass and copper candidates as in Table (1) Prom the graph of figwe 7190 plot blw decrease in ductility and percent cold work). note the maximum cold work needed, at of. El for steel, brass and copper Candidates a Table.Cf). Tabulate the seading ay Tale (1) Metal .cold work (C) aty (310 NPA) 1.cold work (1-0) at 1. EL274) steel Anyolc 0-10 Brass > 144.0 <18-C copper >351.0 29.110 The candidate is suitable for the alloy when both the capabilities lie in a specific Region.

compare and observe from Table 1). to <186%. Of brass only the Region between >14..C Satisfies onder both conditions. Hence, the suitable candidate is brass.