Metal injection molding (MIM) is a hybrid technology which integrates the shaping capability of plastic injection molding and materials flexibility of conventional powder metallurgy. MIM is preferred for mass manufacturing of small, intricate geometric components of a variety of materials as it can achieve 95% to 98% of its wrought materials properties at a much lower cost.

Technology
The initial step to MIM is material selection and preparation. Once the appropriate combinations of metal powder and plastic binders are blended and compounded, an injection moldable feedstock is produced.
Using an injection-molding machine, the parts produced are then subjected to a binder removal process. Depending upon the type of binder used, different methods of debinding are applied.
The parts, after debinding, then go through a sintering process to ensure the parts are of the right material composition, physical properties and correct geometry.
Success Stories
MIM End Effectors Improve Cost & Quality
Patented Rolled Tube Technology
MIM Process Eliminates Sharpening
Advantages
Greater design freedom
With MIM, parts can be designed and manufactured with minimal design restrictions. In addition, almost all design changes are possible within the shortest development cycle and turnaround time.

Complex and intricate shaped parts
MIM is ideal for producing complex-shaped components as well as parts that require assembly or multiple steps to put together.
High production requirements
MIM is most beneficial in high volume production of small precision parts with complicated design geometry. The process lends itself to automation where high volumes and consistent quality are required.

Miniaturization
MIM technology is the best viable process for producing miniature parts economically.
MIM vs. Machining

The MIM Advantage:	Conventional Machining:
Ideal for complex shapes	Design limitations
Highly automated process	Labor intensive process
Lower Cost	Costly Process
No secondary operations required	Possible secondary machining steps
Virtually no material waste	Significant material waste
High production volumes	Lower production volumes
Molding from a single tool	Muliple set-up operations required
Mold the part net shape	Complex shapes require multiple operations
Thin-wall sections possible	Thin walls difficult to machine
Exterior & interior threads possible	Difficult to machine internal threads
Words & numbers can be molded into parts	Machining words & numbers not viable

Applications
MIM technology has found increased applications in the commercial world – from home appliances to watches, automobiles to aerospace, and medical to orthodontics.
Materials
Due to the flexibility of MIM technology, it is possible to customize material compositions according to the specific attributes required by the customers. Some of the compositions are stainless steels, low alloy steels, carbon steels, Ni-alloys, tool steels and tungsten alloys.

 

 

Metals

Materials	Grades	Density (g/cm3)	Hardness (Hv 10)
Stainless Steel	17-4PH	7.6	230
	304L	7.8	120
	316L	7.85	120
	317L	7.85	150
	430L	7.55	120
	440C	7.55	550
Low Alloy Steels	4140	7.4	130
	8620	7.4	190
Carbon Steels	Low	7.7	80
	Medium	7.6	130
	High	7.4	320
Fe-Ni Alloys	FeNi2	7.6	90
	FeNi 8	7.7	100
	FeNi 50	8.05	120
Cobalt Alloys	Kovar	7.8	150
	49Co-2V	7.8	400
Tool Steel	M2	8.05	800 (HT)
Tungsten Alloy	WHA	18	450