The base structure of the component has a known density, which is used to determine the amount of open porosity. A measured amount of copper is selected matching the amount of porosity to be filled. The copper fills the porosity during the sintering process (at temperatures above the melt temperature of copper) simply by placing the copper against the component prior to sintering. The >2000°F sintering temperature allows for the molten copper to flow into the component porosity through capillary action. Sintering is completed on a carrier (e.g. ceramic plate) so the copper stays on the component. Once the part is cooled, the copper is solidified within the structure.
Top Photo (right): Parts assembled with copper slugs ready for sintering. (Photo by Atlas Pressed Metals)
Bottom Photo (right): Microstructure of a part showing how copper infiltrates open porosity. (Photo by Dr. Craig Stringer - Atlas Pressed Metals)
Metalworking is a field that has undergone eons of changes and yet still remains a crucial part of everyday life. Today, techniques are far more sophisticated than those of our ancestors, yet they still retain the same basic function: to customize the shape and properties of metals so they can perform in specific and sometimes unique ways.
|"No metalworking process is quite as effective as powdered metallurgy."|
To that end, no process is quite as effective as powder metallurgy. Through careful combinations of metal powders, heat, pressure and other factors, powdered metal manufacturers are able to produce a wide array of pieces. These parts are durable enough to withstand end use but inexpensive enough to provide a cost-effective solution. For this reason, powdered metals can be the preferred choice for companies that use metal components.
As for how to know which powdered metal supplier offers the best product? Much of that information can be gleaned through the equipment used. Here are three things to look for:
1. In-house testing procedures
No one knows how to ensure powdered metal quality like the producer itself. By holding themselves to rigorous standards, the best powdered metal suppliers can guarantee parts' quality before the product leaves the plant. But that testing doesn't only extend to the finished product - the raw material must first undergo close scrutiny to make sure it's of the highest possible quality. Metal powder is not the stuff swept up off the floor, it's a high-grade powder made from metal cores.
|A great metal parts manufacturer needs the best equipment at its disposal.|
2. Access to the best technology available
Just because a manufacturer has excellent testing practices doesn't mean the equipment used is capable of reading the most granular details. On the other hand, regarding powdered metal manufacturers with access to state-of-the-art equipment like a metallograph microscope, stereoscope, scanning electron microscope (SEM), density scale and carbon analyzer, one can be certain the level of testing done is high-caliber. Plus, some of the top producers have access to engineering laboratories at universities, which adds another dimension to their capabilities.
3. Sophisticated tooling techniques
The process through which these precision parts are fine-tuned is just as important as any other step in the creation of a reliable product. That's why it is crucial for a powdered metal parts manufacturer to use only the best machining methods and equipment around. These include the CNC Mill, Mori Seike CNC Lathe, Electronic Discharge Machines and others complex tools.
All of this is doesn't suggest that anyone with access to this equipment can turn out fine powdered metal parts. The tool is only as good as its operator. In that regard, the top powdered metal producers use the best of both worlds - top-of-the-line machinery and facilities paired with a team of experts across the board. Not only do these men and women know how to create an excellent part from powdered metal, they also have the tools to do so.
As industries across the world embrace modern techniques of producing goods, shipping products and maintaining business operations, the strive for efficiency has vaulted to the top of the agenda. The benefits of economical practices are twofold - not only will organizations increase margins and benefit financially, they can also reduce their carbon footprint and reduce global energy consumption.
In the U.S., it is crucial for the manufacturing industry to become the model of sustainability. It is industry that drives the American economy, and as more companies build factories in the states as opposed to overseas, the way those organizations implement environmentally-friendly practices will have a big impact going forward. Powdered metals can help a manufacturer reach that goal by providing parts that reduce waste and increase usage of recycled metals.
|"It is crucial for the manufacturing industry to become the model of sustainability."|
Manufacturers look to shake their image
When someone outside of manufacturing envisions a factory, that person will likely picture a grey building filled with powerful equipment that uses up a lot of electricity. Unfortunately, that isn't too far off - the EPA estimates that, as of 2012, 20 percent of CO2 emissions came from the industrial sector.
In addition, existing coal-fired plants will emit 300 billion tons of carbon dioxide over the course of their lifespan, according to a study from Princeton University and the University of California-Irving. Those plants create electricity for people and businesses across the country.
It will be the combination of many smaller, incremental steps that will buck the trend of unsustainable energy use. The switch to powdered metal over wrought or cast metal parts is one of those necessary advancements.
The net-shape concept
If the U.S. wants to reduce its carbon dependency, it could start by reducing the need for coal-generated electricity. One of the ways to do that is for manufacturers to use more efficient methods. That's where powdered metals come in - the powder metallurgy process eliminates steps in the manufacturing process, reduces waste and utilizes recycled materials.
A white paper from the Metal Powder Industries Federation discussed the importance of the idea of net-shape in powdered metal manufacturing. Net-shape means the original shape of a part is close to the end product - in other words, there is limited need for additional shaping, leading to more efficient materials use.
In the case of a truck transmission notch segment, powder metallurgy can eliminate 11 steps from the original manufacturing process, bringing the total from 17 steps to six. The remaining powdered metal process requires 1.243 kWh per part, as opposed to the original 2.847 kWh. In addition, any metals not used in the powder metallurgy process can be recycled again, resulting in a 95 percent material utilization rate. By comparison, the material utilization for the original manufacturing process for this specific truck transmission piece was a mere 54 percent.
Net-shape is integral to the environmental benefits of powdered metals. The high material utilization minimizes these manufacturers' contributions to landfills and the energy saved by eliminating steps in the process reduces plants' carbon footprint.
|There's no reason manufacturing and sustainability can't coexist.|
Powdered metal parts can improve end use efficiency
The benefit that powdered metals can have on economical practices does not stop at the manufacturing level. These materials can have an impact at several levels, from that first point of creation all the way down to end use.
Once the custom metal parts are furbished, they become a component of some other product, be it automotive, appliance or otherwise. But before the piece is even incorporated, an organization can tweak the part's design to make it even more efficient. That could mean combining two smaller components into a single unit or reshaping the piece altogether. The right metal products company will work with the manufacturer to find the most efficient design possible.
Then, once that metal piece is part of a car, washing machine and so on, it continues to improve efficiency. Powdered metals can be impregnated with lubricant that lasts the lifetime of the part, allowing it to reach optimum performance and cut down on excess grease.
In these ways, powdered metals can position themselves as the green - and more logical - alternative to other, traditional metal working techniques.
Improper lubrication practices are a good way to ruin a product, machine or process. Many manufacturers realize the dangers of under-lubrication - increased friction and heat, and ultimately, a ruined bearing or joint. But it isn't just a lack of lubrication that can limit an item's effectiveness and lead to a premature death - too much grease or the wrong type can also have devastating effects. Too much of anything is a bad thing, and lubrication is no exception.
Unfortunately, these plant managers and manufacturers often use too much lubrication and are subsequently flummoxed when their product still fails before the expected date. When excess lubricant is present, it tends to build up around the edges and gums up the works. Then, friction still increases and the resulting heat damages the device.
|Too much of anything is a bad thing, and lubrication is no exception."|
Sintered parts offer an easy solution
What if a bearing could somehow self-lubricate - if it could dispense lubricant as needed without using too much or too little? That would greatly reduce maintenance costs, the need for replacement parts, not to mention improve the function of a bearing and the machine it is a part of.
That technology is not a pipe dream - it is a real, working application that powder metal parts can provide. The best metal products company can impregnate its precision parts with a high-grade lubricant that will keep a piece greased for the entire duration of its lifecycle.
The implications of this unique property are numerous and significant. With oil-impregnated sintered metal parts, plant maintenance managers won't have to spend time, effort and money continuously greasing the various pieces of equipment in a plant. They can rest assured that these parts will do that work for them.
|Improper lubrication can damage engine parts.|
Another demonstration of powder metals' effectiveness
Oil-impregnation is just one of the benefits that sintering has to offer. It is the unique composition and variation allowed by the powder metallurgy process that opens up an array of possibilities for manufacturers. Not only can the parts eliminate the need for constant lubrication, they can eliminate the need for certain parts altogether.
Metal sintering allows manufacturers to create new parts that combine several smaller, individual metal components. By consolidating these parts, a company can save money and time, expedite its production and improve its equipment or product efficiency. Traditional metal working techniques make this type of customization overly expensive, and huge companies won't waste their time with individual needs. But the best powder metal companies will gladly take on both of these requests.
Even now, in this age of technological progress and efficiency, there are manufacturers whose methods and designs have not evolved. These organizations have stuck with the componentry they've been using for years - granted, these may work, but not always with optimum efficiency, flexibility and price point. In other words, these manufacturers are settling for what's worked rather than including part design and material among their continuous improvement methods.
In some industries, this thinking may be forgivable - but in every sector, the ability to maximize profits without sacrificing quality has immeasurable benefit. In evaluating cost and performance improvement, manufacturers would be wise to consider the opportunities that powdered metal can provide. Three primary draws come to mind:
|Manufacturers would be wise to consider powdered metal."|
1. Strength to rival other processes
There is an unwarranted opinion among veterans of manufacturing that the powdered metallurgy process does not yield strong, reliable parts. Perhaps when the industry was brand new, over a hundred years ago, that may have been the case. But nowadays, powdered metals offer just as much tensile strength as other comparable processes.
That isn't to say that powdered metal parts are the ideal solution for every situation. But in many cases, it is - that's why manufacturers should work closely with a dependable metal products company to determine the best approach to parts design.
2. Flexible design options
Speaking of working with a sintered metal parts provider, an organization can also improve the very size and shape of the metal components they use with the right guidance. In some instances, the design team may reconfigure two parts that could be cheaper and more effective as a single unit, or vice versa. However, their process could be tailored to create that part as is and might not allow for that type of design change.
The best powdered metal manufacturers work with clients to determine the best possible design for the parts needed. That includes price point, implementation, quantity - all of it. In this way, a company can get an outside recommendation that could point them in a previously unknown direction.
|Powdered metal's design flexibility can benefit the end product.|
3. High quality, low price
The above reasons are nice, but they won't always sway a manufacturer to convert its parts to powder metal materials. However, the price point will. In a perfect world, a company - let's say a car manufacturer - will purchase a large order of automobile components at a reasonable cost with confidence that the parts will hold up. The last thing a car maker needs is for its bearings in the engine to sabotage a vehicle's performance.
Powder metals offer that quality control in a more affordable package than wrought metals or other metalworking processes can. A few industries have already made the switch over to powder metals for these very reasons, including automotive and engineering systems. However, a number of manufacturers have yet to realize the powder metal advantage. But these companies would be well-served to conduct some research of their own and reach out to a sintered metal products company and discuss how alternatives to machining and casting can improve their products or reduce their costs.