Metallurgy cold work

Compression of the hot, spongy metal before cold-working is the novel feature of Knight s method and it represents an important advance in the history of platinum metallurgy. However, even the improved process failed to give consistent results. Knight never produced malleable platinum himself, nor did anyone else who used his published procedure. 

Physical Metallurgy. All commerical metal com-ponents are polycrystalline and all metal lattices contain both point and line faults. Heat treatable alloys frequently contain precipitates which may be very small (< 5 pm dia). All alloys contain major alloying elements but they contain also a range of nondeliberate elements, both metallic and nonmetallic in nature. It is possible to show that all these factors, as well as surface finish, residual cold work and metallurgical history (what was done to the alloy in bringing the component to its present shape) may have an effect on... 

SCC in alloys is controlled by the alloy sohd solution composition, grain boundary segregation, alloy phase transformation, duplex structure, and cold work. SCC metallurgy is discussed in detail in Chapter 9. 

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