This article will introduce one of the most important metal manufacturing processes
in today's world: powder metallurgy. We will learn a little about the basics of
powder metallurgy techniques, how they work, and some of the technique's major
benefits. Hopefully, the end result will be a better understanding of how
sintering and other metallurgy solutions can help you achieve your industrial
What is Powder Metallurgy?
Powder metallurgy is a technique used across the world to process metallic
powders into useful materials. Thanks to its
extreme versatility, powder metallurgy is becoming ever more popular across all
At its simplest, the technique involves using specially formulated powders,
which are compressed and subsequently sintered in vacuum furnaces. This causes the powders to chemically bond, producing alloys which can
have a wide range of properties, depending on the industrial task involved.
Recent years have seen powder metallurgy experience a surge in popularity,
relative to alternative metallurgical techniques such as die casting.
reasons are simple: powder metallurgy allows users to create high-quality
components, while near-net-shape dimensional control provides a high degree of
control over the manufacturing process, facilitating the production of complex shapes.
Different Technologies that involve Powder Metallurgy
Now let's expand things a little, by introducing some of the main types of
powder metallurgy. There are three major variants of powder metallurgy, and each
has their own specific applications. These techniques are as follows:
- Conventional Press and Sinter Powder Metallurgy (PM)
- Additive Manufacturing (AM)
- Metal Injection Moulding (MIM)
The technique users choose generally depends on their needs and budget.
Additive manufacturing is also less suitable for mass production, but is highly
suited to bespoke metallurgy, so is regularly used by artists and engineers
working on one-off projects, where costs are less important than quality. By
contrast, standard powder metallurgy can be integrated into mass production
systems relatively cheaply.
Looking at Powder Metallurgy in More Detail
Of the four types of PM listed above, there are a couple that we are really keen
to highlight: conventional vacuum sintering (PM), and Additive Manufacturing
Firstly, vacuum sintering involves using a vacuum furnace to
generate high temperatures to chemically compact and densify metallic powders, resulting in products with the properties that users
Vacuum furnaces are preferred, because they reduce the
risk of oxidation, resulting in more even atomic diffusion and more reliable
results. Before the sintering phase, it is always necessary to debind components,
preparing them for processing. As debinding generates potentially damaging waste
gases, sintering furnaces will often be independent of debinding equipment.
However, vacuum debinding can integrate the two processes.
workshops using vacuum sintering will need to decide which method to use.
Additive Manufacturing could be seen as an updated version of
In a similar way, it involves manufacturing powders
into the desired shape, then applying heat to give them the correct
properties, but there are some significant differences.
In AM systems, die
moulding of metallic powders is replaced by cutting edge techniques. This could
include laser metal fusion, electron beam melting, or selective laser
melting. In any case, these processes generate the finished result from
digital images, which are often created using CAD packages. This has made AM
very popular among architects or product designers, who use it to create
prototypes for their designs. But it is becoming ever more popular among
high-end manufacturers who rely on custom-formed components.
It's also important to note that both of these processes don't use metal powders
alone. One of the great strengths of powder metallurgy is the way that other
materials can be incorporated into the process.
These include advanced composite
and ceramic materials.
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What are the Advantages of Powder Metallurgy?
Now that we know about the most important types of PM, let's look in more
general terms at what this technique has to offer.
When we look at PM in more detail, we see that it has many advantages over these
Most importantly, powder metallurgy ensures a high level of
precision. Alloy powders are compacted in a die into the correct shape, then
sintered in precisely calibrated furnaces, where they chemically bond. This
results in a high degree of uniformity in the shapes produced, and in many cases
very little machining is needed after that point.
In fact, there are some shapes which can only be reliably manufactured using
powder-based metalworking techniques. These could include radial projections,
parts with unusual curvature, or eccentric elements.
Generally speaking, if a
metal part requires irregular notches, slots or curves, it will be easier to use
powder metallurgy to achieve the desired shape than by using standard machining
PM users are therefore able to expand the range of shapes they are able to
But there are other ways that this technique makes it easier to
customise metalworking processes. By using powder metallurgy, technicians can
control properties like porosity and tailor densities, strength and heat
At the same time, the process is highly repeatable, while generating
minimal amounts of waste. So it's easy to see why PM is being embraced
Understanding Whether to Use Powder Metallurgy or Not
Now let's try to offer some advice to companies who are considering whether to
implement a powder metallurgy-based manufacturing solution. Despite the
qualities we noted above, it's still true that not all metal formation tasks are
appropriate for PM, and choosing the correct type of PM is also critical. It
might help to think about a few criteria to consider while you make your
- Cost - PM can deliver reduced processing costs in some situations.
generally true where users require an optimal lifecycle performance, and where
the components produced will be used in conditions involving extreme heat or
corrosion. In these cases, PM can create components with impressive durability
and reliability. That's why it is often used for manufacturing parts like saw
teeth for industrial machinery, or aviation components.
- Narrow tolerances - Secondly, PM can be an excellent solution when you need
to manufacture parts to very narrow tolerances.
This applies whether the parts
in question are simple or extremely complex, and it is possible to produce most
pieces without a drastic increase in costs or quality. So if you are comparing
precision casting techniques to powder metallurgy, PM can often be the right way
- Sustainability - Powder metallurgy is also a more environmentally friendly
metal processing technique than options like casting and machining.
its net-shape capabilities, PM ensures very low waste levels when shaping
components, helping companies hit their environmental targets.
So, when you assess the right technique for your next metal production
challenge, it's a good idea to bring powder metallurgy into the equation. With
its cost effectiveness, low waste levels and precision, it would be an
appropriate solution for numerous industrial organisations.
How Have Industrial Manufacturers Used Powder Metallurgy?
Industrial manufacturers across the world are constantly coming up with new ways
to use PM. That's not a surprise, because the technique would be a neat fit for
almost any situation where manufacturers desire minimal waste and a high degree
Here are a few recent examples of how PM has been integrated into global
- Automotive gears - PM is now a go-to technology for leading car makers, as
its cost has declined compared to cast-finished steel or iron varieties.
works well with helical, bevel and spur type gears, and has also been used to
create gears for everything from tractor transmissions to heavy-duty oil pumps.
Manufacturers love it because of its precision and efficiency, but also because
it allows them to minimise the weight of their gears without losing
- Turbine discs - PM has also been incorporated into the aerospace and power
HIP in particular has become a regular part of jet engine
production, and will commonly be used to manufacture gas and wind turbines,
often featuring nickel super-alloys, as well as titanium components.
- Medical devices - The healthcare sector has benefited from PM's development,
especially in the production of small-scale precision components.
So you'll now
find PM-made parts in all kinds of medical tools and equipment, delivering
reliable performance and saving lives.
Choose the Ideal Metallurgy Solution For Your Needs
If you need to create precision-engineered components with high strength,
corrosion resistance and heat tolerance, and you want to minimise the need for
machining and waste, powder metallurgy could be the right solution.
While additive manufacturing is the most specific, tailored approach available,
conventional powder metallurgy (or vacuum sintering) continues to offer a viable
and cost effective production option.
So think about which method works best for
your unique needs.
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