MIM (Metal Injection Moulding)

MIM (Metal Injection Moulding) is essentially a technology for producing complex shape parts in high quantities. If the shape allows the production of the part by, for example, conventional pressing and sintering, MIM would in most cases be too expensive.
However, if the required number of complex parts is higher than a certain amount MIM is cheaper than machining.
The effect of the volume production on cost shows that, for example, for the smallest part weighing 4.5g the cost per part falls from $1.4 for an annual production of 250,000 pieces to $0.2 for 3 million or more.
This figure also shows the influence of part size on the cost factor – the bigger the part the smaller is the gap between the cost of 250,000 and 3 million pieces.
A typical competing process to MIM is investment casting and the table below compares the characteristics of parts produced by the two processes.
Table: Comparison of parts manufacturing processes in terms of shaping capabilities.
In regard to many features MIM comes out on top.
However this does not tell the whole story,and many shapes that are possible by MIM cannot be produced by other routes.
MIM certainly has advantages compared with investment casting in the case of high part numbers of castings, and of course in non-castable alloys.