ME 366 Study Guide - Final Guide: Knoop Hardness Test, Cemented Carbide, Work Hardening
Document Summary
Three types of static stresses to which materials can be subjected: perfectly elastic- fractures rather than yielding to plastic flow. Brittle materials such as ceramics, cast irons, and thermosetting polymers. Not good candidates for forming operations: elastic and perfectly plastic-stiffness defined by e. k=y and n=0. Metals behave this way when heated and recrystalilize rather than strain hardening during deformation: elastic and strain hardening- obeys hook"s law in the plastic region. Stress-strain relationships - tensile properties; concepts and quantitative: know the graphs on pg. 46: engineering and true stress-strain; strain/work hardening; flow curve. Flow curve = o= k(true strain)^n: testing, failure, mechanical properties. Bending/ flexural test- test the strength of materials, two supports and load applied at its center of material. Torsion test- as torque is increased the the tube deflects by twisting. Cleavage- failure mode associated with ceramics and metals operating at low service temperatures, which separation rather than slip occurs. Tranverse rupture strength- (1. 5fl)/bt^2)- strength value from test.
