Powder Metallurgy Questions and Answers – Production of Sintered, Non Porous Bearings and Composition

«
»

This set of Powder Metallurgy Multiple Choice Questions & Answers (MCQs) focuses on “Production of Sintered, Non Porous Bearings and Composition”.

1. For bronze bearings, the amount of shrinkage _______ as the particle size of powder mix decreases.
a) decreases
b) increases
c) constant
d) moderate
View Answer

Answer: b
Explanation: In the production of bearings by P/M route, powder characteristics like particle size and distribution, and particle shape play an important role. In the bronze bearings, decrease in the particle size of elemental tin or copper powder increases the amount of shrinkage.
advertisement

2. Which of the following material on addition to the powder mix lowers the strength of the bearing?
a) Oil
b) Lead
c) Bismuth
d) Graphite
View Answer

Answer: d
Explanation: The addition of graphite improves lubrication but also results in growth and lowers the strength of the bearings. Lubricants used in the mix have significant effect on the apparent density and flow rate but very little influence on the dimensional change.

3. Which of the following bearing doesn’t belong to the class of non-porous bearing with steel backing?
a) Copper-antimony alloy
b) Aluminum based alloy
c) Copper based alloy
d) Babbit
View Answer

Answer: a
Explanation: The major types of bearings which belong to the class of non-porous bearing with steel backing include: aluminum-based alloy, copper-based alloy, and babbits. Bronzes and aluminum alloys are more common than babbits because of their higher load carrying capacity.
advertisement
advertisement

4. Which of the following powder production method is used for the production of non-porous bearing with steel backing?
a) Mechanical alloying
b) Gas atomization
c) Water atomization
d) Electrolysis
View Answer

Answer: b
Explanation: The pre-alloyed powders for the production of non-porous bearing with steel backing are manufactured by gas atomization. In this process the molten metal stream is disintegrated using high velocity argon, nitrogen or helium gas jets and the atomized powders are collected in a water bath.

5. Lower lead content in copper-lead alloy is undesirable.
a) True
b) False
View Answer

Answer: a
Explanation: Copper with 30wt% and 40wt% lead is commonly used for production of bearings. Lower lead content gives better strength but poor surface (anti-seizure) characteristics whereas higher lead contents (40wt%) ensure better lubrication.
advertisement

6. What should be amount of tin in copper-lead alloy containing 25% lead for production of non-porous bearing?
a) 14 – 20wt%
b) 4 – 10wt%
c) 1 – 5wt%
d) 11 – 15wt%
View Answer

Answer: b
Explanation: The amount of tin in copper-lead alloy containing copper with up to 25% lead for production of non-porous bearing is 4 – 10wt%. Addition of tin not only improves the strength but also increases the seizure resistance, and oil corrosion is reduced.

Sanfoundry Global Education & Learning Series – Powder Metallurgy.

advertisement

To practice all areas of Powder Metallurgy, here is complete set of 1000+ Multiple Choice Questions and Answers.

Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!

advertisement
advertisement
Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer & SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage, Advanced C Programming, SAN Storage Technologies, SCSI Internals & Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him @ LinkedIn | Youtube | Instagram | Facebook | Twitter