List four major differences between deformation by twinning and deformation by slip relative to mechanism, conditions of occurrence, and final result.

Answer: The four major differences are: 1. Mechanism - Deformation by twinning involves changes in crystal lattice orientation through the formation of mirror-image regions (twins), while deformation by slip involves the movement of dislocations and shearing of the crystal structure. 2. Conditions of occurrence - Twinning usually occurs at low temperatures and high strain rates, whereas slip occurs at high temperatures and low strain rates. 3. Final result - Twinning results in a more intricate microstructure, often exhibiting better mechanical properties, while slip results in a permanent distortion of the crystal lattice with the formation of dislocations. 4. Ductility and strain hardening - Twinning is more common in materials with low ductility, while slip is more common in ductile materials. Strain hardening is more prominent in materials deformed by slip, whereas twinning causes less strain hardening due to twin boundaries acting as barriers to dislocation motion.