For preparation of porous bearings by powder metallurgy, preferred particle shape is___________________?

Related Mcqs:

1. Powder metallurgy process does not make metal powder by_________________________?

   A. Atomisation
   B. Grinding/milling
   C. Hammering
   D. Electrolytic deposition

2. Powder metallurgy technique is used in the production of ____________________ tools ?

   A. Tungsten carbide
   B. High carbon steel
   C. High speed steel
   D. Drilling

3. Carbide tipped cutting tools are manufactured by powder metallurgy techniques and have a composition of_____________________?

   A. 90% tungsten carbide and 10% cobalt
   B. 70% aluminium oxide & 30% silica
   C. 30% nickel, 15% chromium & 55% tungsten
   D. 65% tungsten & 35% zirconium

4. Powder metallurgy is used to produce__________________?

   A. High precision components with complex cavities and sharp features
   B. Components of large size
   C. Porosity free components
   D. Components of such alloys whose constituents do not form alloys readily

5. Which of the following can be manufactured using powder metallurgy techniques ?

   A. Brake linings
   B. Bearings
   C. Carbide tool tips
   D. All A, B and C

6. A particle is settling in a liquid under Stokesian conditions. The free falling velocity of the particle is proportional to____________________?

   A. √(Particle diameter)
   B. Particle diameter
   C. (Particle diameter)2
   D. (Particle diameter)3

7. Identify the correct statement with reference to the extractive metallurgy of aluminium ?

   A. The electrolyte consists of molten Na3AlF6 with approximately 1 to 8% Al2O3
   B. Approximately 80% of the aluminium deposited on the cathode comes from cryolite
   C. Sodium is deposited along with aluminium, but is immediately vaporised
   D. Anode effect sets in when the cryolite concentration goes below 40%.

8. Tin based white metals are used, where bearings are subjected to___________________?

   A. High pressure & load
   B. Low pressure & load
   C. High temperature
   D. Large surface wear

9. Property responsible for the talcum powder to cling to the skin is the__________________?

   A. Capillary action
   B. Adhesion
   C. Cohesion
   D. Surface tension

10. Alloy powder manufactured by the following process have spherical shapes ?

    A. Electrochemical deposition
    B. Gaseous reduction
    C. Atomisation
    D. Mechanical attrition