True or False: (32') 1. In a crystalline material, the movement of the dislocation allows deformation to occur under a lowerstress than in the perfect lattice. 2. Generally, BCC crystalline

metals are softer than FCC crystalline metals. 3. The necking phenomena could be observed in both tensile and compressive tests. 4. Thermal expansion is the name for the effect of temperature ondensity. 5. Wood, metal and plastic are generally used to make patterns in plaster-mold casting process. 6. Inverse lever law only works in solid-liquid phase transformations, not works in solid-solid phase transformations. 7. At room temperature, metals become harder and stronger when they are plastically deformed, this is called strain hardening. 8. Flow curve values (K and n) from tensile test data can be applied to compression operations for metals. 9. Rapid cooling of austenite steel results in compressive residue stresses on the surface. 10. Ceramics are substantially stronger in tension than in compression. 11. In metal casting, during the pure metal solidification process, the large columnar grains orient towards the center of the casting. 12. Through alloying, it is possible to increase strength, hardness, and other mechanical properties compared to pure metals. 13. The substitutional solid solution is a multi-phase structure with one phase dissolved in another. 14. Glass-ceramics is a ceramic material produced by conversion of a glass into polycrystalline structure through heat treatment. 15. The hardenability of a material refers to its maximum hardness that can be attained throughmartensite formation process. 16. In metal casting, the function of a riser is to continuously supply liquid metal to compensate for shrinkage of the part during solidification.

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