near net shape production of metal infection moulding

1. Near Net Shape (NNS)
Production
Ankit kumar (13BME0072)
Arjun singh (13BME224)
Dhruv Saxena (13BME0072)
Venkateshwar Rao (13BME0571)

2. Table of content
• Introduction
• Objectives
• Problem definition
• Literature
• Proposed methodology
• Summary
• References

3. Introduction
• Net-shape and near net-shape, subsequently referred to as just net-shape,
manufacturing can be defined as ‘the manufacture of a component or section
of a component by consolidating material with minimal loss or wastage’. Two
types of net-shape manufacture are envisaged; Additive processes based on
high energy sources to consolidate wire or powder, for example, shape metal
deposition (SMD) and direct laser deposition (DLD); Temperature and
pressure activated consolidation of powder or fabricated structures,
• for example, metal injection moulding (MIM), Forging Process,
Additive layer manufacturing (ALM)

4. Objectives:-
• To Reduce material cost:- Most of the material in the form of wire or
powder is used to directly build the componentshape with little
overstock or other wastages.
• To Reduce ‘Removal’ operations:- Heavy machining or roughing
operations are eliminated and finish machining is kept to a minimum
which results in less swarf, low energy consumption, and less work in
progress (WIP) together with associated lower risk of scrapping and
enhanced rapid prototyping capability.
• To Enhance Product Opportunities.

5. Problem Definition
• Is using Near Net Shape (NNS) injection moulding a better way to
manufacture products.
• Potential Detractions
– Higher cost of manufacturing machines, i.e debinding ,sintering process
– Usage of materials at higher rate in MIM process than any other
methods.
• Can Hardness and Fatigue properties of products manufactured with
NNS
Moulding match with those of “traditionally” manufactured products?

6. Literature:-
• Metal powders for the MIM process are mixed with thermoplastic
binders and plasticisers to obtain a homogeneous feedstock in the
form of pellets.
• The spherical metallic particles are normally in the range of 5-15µm
and represent around 70% by volume of the mixture which is fed as
thermoplastic material into injection moulding machines working at
temperatures of 100°C to 250°C.
• The resultant ‘green’ parts have the geometric features of the finished
article, apart from being enlarged, and are rigid enough to be handled

7. • Debinding
During the debinding stage, the binder and plasticisers are mostly
removed and remaining traces are purged during the subsequent sintering
operation. Debinding is usually performed by thermal decomposition and
evaporation, chemical decomposition, or extraction with liquid chemicals.

8. • Sintering
Sintering takes place in a vacuum or protected atmosphere furnace and causes a
linear shrinkage to achieve 95-99% density in the part. This is normally the finished
condition ready to be assembled or to undergo secondary operations such as
surface hardening.
For aero-space components it may be necessary to HIP( Hot isostatic pressed) the
sintered part to reach full densification, made possible because the fine residual
porosity is not surface connected.

9. Proposed Methodology
• By using MIM process gives better finishing products with minimal amount of
machining processes.
• A tolerance band of ±0.3% of the nominal dimension can be regarded as a good
guideline for designing MIM parts to reduce costs in aero-engines.
• impart mechanical properties.
• MIM part shrinks by about 20 percent during the debinding and sintering
processes.
• the MIM part becomes soft and responds to gravity during the sintering process

10. Summary
• Net-shape powder consolidation has a major role to playing reducing
the cost and environmental impact in the manufacture of future
military engines from small intricate to very large and complex
components.

11. References:-
[1] Metal Injection Moulding of Aerospace Components. David Heck.
Proceedings of IMEC, Sheffield, UK. May 2005.
[2] http://www.custompartnet.com/wu/metal-injection-molding
[3] The Role of Net-Shape Manufacture Reducing LifeCycle Costs of Gas Turbine
Components. D Rugg, D Fray. TMS Conference (The Minerals, Metals & Materials
Society), 2004
[4]
http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.highlight/abstract/
1249/report/F