this is a materials course TRUE or FALSE 1. The diffusion rate is more dependent
ID: 2086839 • Letter: T
Question
this is a materials course
TRUE or FALSE 1. The diffusion rate is more dependent on time than on temperature. ( 2. Solid-solution strengthening does not always cause a reduction in ductility 3. Brittle fracture has a low energy absorption. ) 4. A tie line cannot exist in one phase region. 5. The hardness of martensite is dependent on the cooling rate.O 6. A polymer can never be 100% crystallized. () 7. The breaking strength of a fiber composite loaded perpendicular to the fibers is in between the strength of the fiber and the matrix. ) 8. Corrosion takes place by the dissolution of a metal at the cathode. ) 9. A reduction reaction takes place at the cathode. () 10. In ceramics, dislocation motion is responsible for deformation.Explanation / Answer
1. False. Diffusion rate is more depending upon temperature than time. When temperature increases the energy of the molecules will also increase. It increases the bouncing of molecules and improves the diffusion rate.
2. False. Strengthening always reduces the ductility. Strengthening takes place by the dislocation movement. Ductlity get reduced by Grain size reduction. That is it is very difficult for the motion of a dislocation.
3. True. Brittle fracture has low energy absorbtion. Brittle fracture takes place as a result of Tensile stress acting normal to the crystal planes. Also it takes place at comparativley narrow temperatures. There for the energy absorbtion is low.
4. True. Tie line cannot exist in single phase regions because it is a an isothermal line on the phase diagram through the alloy's position when it is in a two phase field, intersecting the two adjacent solubility curves
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.