Comprehensive explanation required as to the atomistic level processes which lead to
1. strengthening of metals by cold working or strain hardening
2. regaining of ductility of strain hardened structures by recovery, recrystallisation and grain growth© BrainMass Inc. brainmass.com October 24, 2018, 6:53 pm ad1c9bdddf
Strengthening Mechanisms of Metals:
Cold-working in a metal involves the plastic deformation at a temperature low enough that the strain-hardened condition is retained by storing the strain energy expended in the plastic deformation in the form of dislocations and other imperfections. The strain hardening occurs at low temperatures where recovery is very slow or does not occur at all. It is a very convenient mechanism of metal strengthening. Strain hardening is the increase in strength cased by an increase in the dislocation density resulting from a given plastic strain. The new dislocations that are created from the cold-working must interact with the dislocations that already exist. As more dislocations are created, it becomes more difficult for them to move through the high density dislocation cluster that now exists within the metal. This causes the strain hardening.
This solution answers two questions on atomistic level processes about strengthening metals through cold working and strain hardening and recrystalization.
PPR Educational Questions
I am having difficulty with the following questions. The task is to give a two paragraph response to each question,as well as come up with several examples for question 5.
1. What is Bloom's Taxonomy? Describe each level. Speculate as to why the State of Texas advises teachers to use it in planning instruction
2. Identify the acronyms TEKS and TAKS. Discuss their relevance to Texas teachers and students.
3. What is the difference between instructional goals and objectives? Discuss the planning process with regard to these terms as well as instructional alignment.
4. Analyze the benefits to using an integrated or thematic approach to instruction.
5. What is cooperative grouping? Include several examples and explain why teachers should regularly include small group instructional activitiesView Full Posting Details