Powder metallurgy technology has come a long way. While some sectors have stalled in the last few decades, the more thrill-seeking of us suppliers and customers are innovating on an almost-daily basis.
The many surprising, creative, and cost-effective uses of powder metallurgy (PM) are being incorporated by engineers and purchasers in:
- Automotive
- Lawn & garden
- HVAC
- Aerospace
… and other industries to take their products to the next level.
If you haven’t been keeping up with recent and potential innovations in the powder metallurgy industry, here’s some insider info to help get your creative side a little more excited about PM:
4 Advances in Powder Metallurgy Technology
1. Ultra-High-Temperature Sintering
You are probably aware of the benefits of sintering, and you may have brushed up on high-temperature sintering at one point. But what about one of the ultra-recent (so recent we’re still working on it) advances in powder metallurgy -- ultra-high-temperature sintering?
Ultra-high-temp sintering is used primarily for structural applications, and is an effective processing technique for applications demanding exceptionally high performance of the material system. Ultra-high-temp is basically a further improvement of what high-temp sintering achieves, taking several properties to new levels, including:
- Tensile strength
- Bending fatigue strength
- Impact energy
Sintering of iron-based powder metal parts is usually performed around 2020-2100° F. About 85-95% of all current PM parts are sintered at this temperature. Generally, 2300° F is the maximum that would be considered high-temperature.
Many parts, such as castings and machined parts, have already been converted to powder metal in recent years thanks to the many powder metallurgy advantages engineers are steadily discovering. Now, as the industry works its way up to forging, those conversions will probably include new alloys and ultra-high-temp sintering.
2. Breaking the SMC Barrier
Soft magnetic composites (SMCs) are an excellent example of the modern PM material, but there are fundamental limitations, such as how to improve permeability while also getting rid of eddy losses, which can cause inefficiency in a motor. One potential new trick is using nontraditional alloys in an attempt to bridge that problem, and broaden a whole application base for soft magnetic composites.
SMCs have an electrically insulating layer … that happens to be magnetically insulated, too. We aspire to have something electrically insulating but also magnetically conductive. Materials exist that have high resistivity, yet conduct magnetism, so the industry is trying to create a unique composite structure with iron.
There are certain elements not traditionally used in powder metallurgy, yet have unique physical characteristics that fit well with the ultra-high-temp sintering process. SMCs are not usually sintered, but we’re exploring its potential as another way your powder metal part can reach a new level of performance!
3. Advances in Automotive Manufacturing
There are many ways that powder metal is helping with the “electrification” of the motor vehicle and the creation of more compact components. No. 1 and 2 on this list will help us achieve more in automotive as ecofriendliness becomes a bigger issue worldwide.
We have noted that the short-term future of powder metallurgy is strong. The North American automotive market has embraced PM and will continue to do so. But look at this with the view that gas prices in the United States are quite low compared to Europe and Asia, and the distances we routinely travel by vehicle are much greater.
Having said that, the trends occurring in Europe and Asia will eventually head overseas. Nobody’s wishing for higher gas prices, but efficiency and eco-friendliness concerns may soon take precedence.
Dr. Anders Flodin, development manager for powertrains at Höganäs, recently published a series of blogs in which Höganäs sponsored the tear-down of three distinct vehicles to evaluate the current and future potential state of powder metallurgy in European, Asian, and North American vehicles. He subjected three vehicles to tear-down:
- Toyota Yaris
- VW Passat GTE PHEV
- Ford F150, 4-wheel drive
Some interesting details from the studies were the use of powder metal in each vehicle. The Yaris has only 0.2% (3.2 kg) of its weight in the form of PM parts. The VW had only 0.3% (4.2 kg) by weight. The F150 had 1.7%, or 32.1 kgs. These differences are very dramatic and potentially scary.
As the world population grows and societies continue to develop, the number of vehicles produced yearly will continue to trend upward. However, where the vehicles are produced and the type of vehicles produced will have a dramatic impact on the worldwide powder metal industry. We’ve seen predictions that, in less than a generation, the number of hybrid and electric vehicles will surpass 50% of all vehicles produced. Unless PM adapts to these changing market conditions through use of emerging materials like soft magnetic composites, how will our industry continue to grow?
Even in the North American market, the landscape is changing. In Anders’ analysis, he noted that the shift from a 6-cylinder engine to a 4-cylinder engine resulted in a 3.6 kg (almost 8 lbs.) loss per engine. Where is the North American auto industry heading -- smaller engines with more horsepower and greater fuel economy (4-cylinder engines)? Once again, quoting Anders: they optimized the design of a pickup truck for hybridization. Their analysis showed this hybrid pick up would have approximately 20 kg of PM parts. Yes, this would be great in Europe and Asia but in North America, this represents a 12 kg loss!
With the North American market going to more pickups and SUVs, the impact could be dramatic.
The question that needs to be answered is, how does the PM industry respond? In the short term, PM manufacturers and their customers can continue to innovate part design and continuously improve current product offerings. In the long term, we can move the needle to:
- Higher-performance press and sinter PM parts
- Better SMC product offerings to facilitate the electrification of the auto
- Continued education and interaction of the PM part end users to understand and exploit its many benefits.
So, if we work on #1 and #2 on this list, here’s where we can go with powder metallurgy in the auto industry.
4. Metal Additive Manufacturing
Some tremendously exciting niche advances in powder metallurgy technology are in metal additive manufacturing, or 3D printing. Additive manufacturing is very attractive for exceptionally unusual-shaped or complex objects that can be difficult to manufacture using other processes. Metal additive manufacturing can also produce multiple parts at a time, usually with less waste material.
Manufacturers are still working out the potential for incorporating 3D printing into their parts production processes. Part of that process is getting past the high price point of 3D printing.
What’s on Your Horizon?
What does your auto, electric machine, lawn/garden, or other small component need? Chances are there’s a powder metal innovation out there that you haven’t leveraged yet.
Consider doing further research into soft magnetic composites, or speak to an advanced powder metallurgy company. Our advances mean nothing if you’re not willing to take advantage of them!
