Page 483 - 04. Subyek Engineering Materials - Manufacturing, Engineering and Technology SI 6th Edition - Serope Kalpakjian, Stephen Schmid (2009)

Qualitative Problems 463

BIBLIOGRAPHY

ASM Handbook, Vol. 7: Powder Metal Technologies and -, and Bose, A., Injection Molding of Metals and
Applications, ASM International, 1998. Ceramics, Metal Powder Industries Federation, 1997.
Atkinson, HM, and Rickinson, B.A., Hot Isostatic Pressing, Kang, S.-]., Sintering: Densification, Grain Growth and
Adam Hilger, 1991. Microstructure, Butterworth-Heinemann, 2005.
Douvard, D. (ed.) Powder Metallurgy, ISTE Publishing, Kuhn, H.A., and Ferguson, B.L., Powder Forging, Metal
2009. Powder Industries Federation, 1990.
Fayed, M., and Otten, L. (eds.), Handbook of Powder Klar, E., and Samal, P.K., Powder Metallurgy Stainless Steels:
Processing, Microstructures
Science and Technology, 2nd ed., Chapman Sc Hall,
and Properties,
ASM
l, 1997. Leander, F., and West, WG., Fundamentals of Powder
International, 2008.
German, R.M., A-Z of Powder Metallurgy, Elsevier, 2007.
Powder Metallurgy and Particulate
Materials
Metallurgy, Metal Powder Industries Federation, 2002.
Processing, Metal Powder Industries Federation, 2006. Powder Metallurgy Design Manual, 2nd ed., Metal Powder
i, Powder Metallurgy of Iron and Steel, Wiley, 1999. Industries Federation, 1995.
REVIEW QUESTIONS

I7.l. Describe briefly the production steps involved in mak- I7. 7. Why might secondary and finishing operations be per-
ing powder-metallurgy parts. formed on PM parts?
l7.2. Name the various methods of powder production and l7.8. Explain the difference between impregnation and infil-
explain the types of powders produced. tration. Give some applications of each.
l7.3. Explain why metal powders may be blended. l7.9. What is mechanical alloying? What are its advantages
l7.4. Describe the methods used in metal powder com- over the conventional alloying of metals?
paction. l7.l0. Why are protective atmospheres necessary in sinter-
|7.5. What hazards are involved in PM processing? Explain ing? What would be the effects on the properties of PM parts
their causes. if such atmospheres were not used?
l7.6. Describe what occurs to metal powders during sintering.

QUALITATIVE PROBLEMS

l7.I I. Why is there density variation in the compacting of l7.I9. The powder metallurgy process can be competitive
powders? How is it reduced? with processes such as casting and forging. Explain why this
l7.l2. What is the magnitude of the stresses and forces in- is so.
volved in powder compaction? l7.20. What are the reasons for the shapes of the curves
l7.l3. Give some reasons that powder-injection molding is shown in Fig. 17.10 and for their relative positions on the
charts?
an important process.
|7.2l. Should green compacts be brought up to the sintering
I7.I4. How does the equipment used for powder com-
temperature slowly or rapidly? Explain your reasoning.
paction vary from those used in other metalworking opera-
tions in the preceding chapters? 17.22. Because they undergo special processing, metal pow-
ders are more expensive than the same metals in bulk form,
|7.|5. Explain why the mechanical and physical properties
especially powders used in powder-injection molding. How is
depend on their density.
the additional cost justified in processing powder-metallurgy
|7.l6. What are the effects of the different shapes and sizes parts?
of metal particles in PM processing?
l7.23. In Fig. 17.11e, it can be seen that the pressure is
l7.|7. Describe the relative advantages and limitations of not uniform across the diameter of the compact at a parti-
cold and hot isostatic pressing. cular distance from the punch. What is the reason for this
l7.l8. How different, if any, are the requirements for punch variation?
and die materials in powder metallurgy from those for forg- l7.24. Why do the compacting pressure and the sintering
ing and extrusion operations? Explain. temperature depend on the type of powder metal?