MCQOPTIONS
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MCQOPTIONS
This section includes 11 Mcqs, each offering curated multiple-choice questions to sharpen your Powder Metallurgy knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Sintering can be considered as an irreversible thermodynamic process. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2. |
It is desirable that sintering stops when ______ |
| A. | ( frac{dA_{SV}}{dA_{SS}} )is close to zero |
| B. | ( frac{dA_{SS}}{dA_{SV}} ) is close to zero |
| C. | <sub>SS</sub> >> <sub>SV</sub> |
| D. | ( frac{-dA_{SV}}{dA_{SS}} )is close to zero |
| Answer» E. | |
| 3. |
To achieve densification during sintering without grain growth, the SS must be _____, while the SV must be _____ |
| A. | Zero, maximized |
| B. | Maximized, zero |
| C. | Zero, minimized |
| D. | Maximized, minimized |
| Answer» C. Zero, minimized | |
| 4. |
The initial free energy of the compact before sintering must be _______ |
| A. | Positive |
| B. | Negative |
| C. | Zero |
| D. | Infinite |
| Answer» C. Zero | |
| 5. |
The driving force for sintering is reduction in ________ |
| A. | Internal energy |
| B. | Surface tension |
| C. | Surface energy |
| D. | Entropy |
| Answer» D. Entropy | |
| 6. |
The process of sintering will stop when _______ |
| A. | dE= <sub>SS</sub>dA<sub>SS</sub>+ <sub>SV</sub>dA<sub>SV</sub>=0 |
| B. | dE= <sub>SS</sub>dA<sub>SS</sub>+ <sub>SV</sub>dA<sub>SV</sub>>0 |
| C. | dE= <sub>SS</sub>dA<sub>SS</sub>+ <sub>SV</sub>dA<sub>SV</sub><0 |
| D. | dE= <sub>SS</sub>dA<sub>SV</sub>+ <sub>SV</sub>dA<sub>SS</sub>=0 |
| Answer» B. dE= <sub>SS</sub>dA<sub>SS</sub>+ <sub>SV</sub>dA<sub>SV</sub>>0 | |
| 7. |
_______ requires mass transport. |
| A. | Pore expansion |
| B. | Grain shrinkage |
| C. | Densification |
| D. | Adhesion |
| Answer» D. Adhesion | |
| 8. |
Which of the following changes do not occur on during recrystallization? |
| A. | Pore shrinkage |
| B. | Phase changes |
| C. | Grain shrinkage |
| D. | Precipitation |
| Answer» D. Precipitation | |
| 9. |
Which of the following are the stages of sintering, according to Sauerwald theory? |
| A. | Adhesion, recrystallization |
| B. | Adhesion, crystallization |
| C. | Adhesion |
| D. | Adhesion, bonding |
| Answer» B. Adhesion, crystallization | |
| 10. |
_______ is the major material transport mechanism in sintering of the single component system. |
| A. | Inter-diffusion |
| B. | Self-diffusion |
| C. | Lattice-diffusion |
| D. | Volume-diffusion |
| Answer» C. Lattice-diffusion | |
| 11. |
Sintering involves _____ types of system. |
| A. | Unary |
| B. | Binary |
| C. | Single component andmulticomponent |
| D. | Ternary |
| Answer» D. Ternary | |