Help me please Help me please Help me please Help me please Help me please Help
ID: 2267017 • Letter: H
Question
Help me please Help me please Help me please Help me please Help me please Help me please Help me please 7. List three methods to strength a soft metal like copper, alumin 8. Given a material with an absorption coefficient (a) of 10 cm, what is the penetration thickness(e) for the intensity of light (1) decays to its (lo) 1/e? (Hint: Beer's law 1 = 10 Exp(-z) ) (5%) .Discuss the challenge and possible solution for the thermoelectric materials from the material science points of views. (Hints: start from the Wiedemann-Franz law: -=constant ledemann-Franz law: ) (10%)Explanation / Answer
Methods to strenth soft metals:
1. Alloying: small amount of alloying element aded to molten copper which forms homogenous microstructure. such as Tin(Sn) added to copper makes Bronze.
2. Percepetation hardning: This also called particle hardning and age hardening. This is a heat traetment which produces uniformly dispersed particles within metal's grain structure. This process involves heat Treatment at high temperature followed by rapid cooling process. Uniformly arranged particles produces stable material which prevent creation and propogation of lattice defect. This process is performed in Vacuum and temperature range 900F to 1150 F.
3. Work hardening: This is the process which strengthen metals by opposing dislocation motion. Dislocations in the element interact with each other by generating stress fields. The interaction between stress fields can impede dislocation motion by repulsive or attractive motion. If two dislocations cross, dislocation line entanglement occurs. These entanglements act as a pinning points, which opposes dislocation motion.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.