Powder Metallurgy

 

Why Powder Metallurgy 

 

What are the advantages of Sintering

1. Very high and uniform purity can be easily achieved
2. The simple fabrication process retains purity 
3. Grain size is easily controlled
4. No deformation is needed to produce directional elongation of grains
5. Void density can be controlled 
6. Objects can be created in any shape
7. Shapes can be produced that not be made by any other process

 

Product cost effectiveness

Powder Metallurgy is the most cost effective of a number of possible options for making the part 
 

Product uniqueness
Some characteristic of the product (e.g. combination of chemical constituents, control over microstructure, control over porosity etc.) can be created by starting from a powder feedstock, which would be very difficult or sometimes impossible in conventional processing

Product cost effectiveness

Product cost effectiveness is by far the predominant reason for choosing Powder Metallurgy and is the main driver of the structural (or mechanical) parts sector. Powder Metallurgy wins the cost competition on the basis of its lower energy consumption, higher material utilisation and reduced numbers of process steps, in comparison with other production technologies.

All of these factors, in turn, are dependent on Powder Metallurgy's ability to reduce, or even possibly eliminate entirely, the machining operations that would be applied in conventional manufacture.

In order to eliminate machining operations, Powder Metallurgy relies on its abilities to form complex geometrical shapes directly and to hold close dimensional tolerance control in the sintered product.

Powder Metallurgy's cost effectiveness generally also requires that the particular product be made in large production quantities. If production quantity requirements are too low, there would be no opportunity to amortise the costs of the (long-lasting) forming tooling over a sufficient numbers of parts or to avoid the loss of significant fractions of potential production time in tool changeover/setting operations.

The production quantities at which Powder Metallurgy would be the process of choice is of course dependent on how difficult it would be to form the shape by a different route, but, in general, would be at least in the order of tens of thousands of parts per year.

 

Processing of materials with very high melting points 
Powder Metallurgy enables the processing of materials with very high melting points, including refractory metals such as tungsten, molybdenum and tantalum. Such metals are very difficult to produce by melting and casting and are often very brittle in the cast state. The production of tungsten billet, for subsequent drawing to wire for incandescent lamps, was one of Powder Metallurgy's very early application areas. 

Products with controlled levels of porosity 
Powder Metallurgy enables the manufacture of products with controlled levels of porosity in their structure. Sintered filter elements are examples of such an application. The other prime example is the oil-retaining or self-lubricating bearing, one of Powder Metallurgy's longest established applications, in which the interconnected porosity in the sintered structure is used to hold a reservoir of oil.

 

PM Process: