The drawbacks of powder metallurgy, which render its use difficult and restricted, ought to be mentioned alongside its advantages. the drawbacks are :
1. Pure metal powders are very expensive to produce.
2. The size of parts produced its limited because of the large presses needed to obtain the compressing pressures resulting in increased tool and press costs.
3. The lack of simple methods of obtaining alloy powders - of steels , bronzes, brasses, etc.,
4. The strength properties of the finished articles are usually lower than those of similar article produced by conventional means.
5. Articles made out of metal powders possess, as a result of their porosity and increased tendency to oxidation throughout the whole body and only on the surface of the article.
6. Powder metallurgy products possess comparatively poor plastic properties (impact strength, elongation).
7. Die design limitations limit the type of shapes that can be produced.
8. Since the dies are very expensive, the process is not practical (economical) unless quantities of at least a few thousand pieces are manufactured.
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