Your browser is out of date.

You are currently using Internet Explorer 7/8/9, which is not supported by our site. For the best experience, please use one of the latest browsers.

Atlas Pressed Metals FAQ and How-To Guide

Welcome to the Atlas Pressed Metals FAQ and How-To Guide, your one-stop resource for answers to common questions and step-by-step instructions on various aspects of Powder Metallurgy. Whether you're new to the field or an experienced professional, you'll find valuable information here to help you navigate the world of Powder Metallurgy.

 

Powder Metallurgy Frequently Asked Questions 

Powder Metallurgy is a manufacturing process that involves forming metal powders into a variety of components  through compaction and sintering. It's used to create a wide range of products, from automotive components to medical devices.

The process typically involves four main steps: powder production, powder blending, compaction, and sintering. Learn more about each step in our Powder Metallurgy Basics section.

Powder Metallurgy offers several advantages, including high material utilization, consistency, ability to form complex shapes, and cost-effectiveness. Explore the Advantages of Powder Metallurgy over other Manufacturing Methods.

Yes, in most cases. Traditionally we are trying to balance the density of a part so that they are similar throughout the part, however, sections of a part have the potential of being designed with lower or higher density.

At lower densities, part porosity is more skeletal in nature, and would enable liquids, such as oil, to pass through the part. However, as part density increases, those "pathways" are reduced or eliminated. 

Answer: Yes. 

Best Practices for Welding Sintered Metals

  • Keep parts free of contaminants 
    • Residual lubricants, coolants or cleaning solution reduces the weld integrity.
  • Select material with a lower carbon content
    • The materials with a 0.0 - 0.5% perform better than the higher carbon blends
  • Use a higher density 
    • Parts with densities above 6.8 g/cc provide improved weld contact areas 

Answer: Yes.

Since powdered metal components are porous, the absorption of contaminants into PM parts poses a difficulty as well as a flame hazard for welding. Preventing contaminants from being absorbed into the part is critical in weld applications.

Simple Test to Identify the Presence of Porosity Contaminants in PM Parts

  • Atlas uses a hot plate test that is also commonly used by our platers, which will show if there are contaminants in the part. This test consists of heating the hot plate to between 150°-350°F and placing the part on the hot plate. The temperature range will depend on the type of contaminant that you might expect to see in the part. A “smoking” part is a tell-tale sign.

Steam treatment is a thermal process that creates a thin controlled oxide layer on the surface of an iron-based metal component.  Steam treatment can provide a component with increased corrosion resistance, hardness, density, and magnetic properties.  It can also be used to seal the porosity and improve its wear characteristic. 

Steam treatment is a batch process with minimal inputs and has been proven to be a cost-effective solution for many applications.  Components transferred to steam treat must be kept clean and dry as it is necessary to avoid contaminants or residue on or in the structure prior to processing because it will impact of how well the oxide layer forms on the surface.

As in most thermal treatments, time, temperature and atmosphere are controlled to provide the optimal conditions for the expected finish.  The desired properties of the component will dictate what time and process parameters are used for a given part. During a typical steam treatment process, parts are placed in a steam treat unit and heated to approximately 1000° F.  Once the component is at temperature, steam is introduced and the water vapor reacts with the iron to form the oxide layer (magnetite - Fe3O4).  After a designated period of time, the component is removed from the unit and allowed to cool. The oxide appears on the component surface as a blue/black finish.

Components are copper infiltrated for a number of reasons. Some basic desired results are improvements to tensile strength, hardness, impact properties, and ductility. Copper-infiltrated components will also have a higher density.  

Other reasons customers may elect copper infiltration are for wear improvement or to block air/gas flow through an otherwise porous component at temperatures that resin may not be practical.  Sometimes copper infiltration is used to enhance the machining characteristics of PM steel; the copper leaves a smoother machined finish.
 
Here's how copper infiltration works:
 
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.

Powdered metal tooling can render these types of testing a costly undertaking but there are alternative options. Unfortunately, it is not feasible to manufacture production components from any sort of temporary tooling. However, prototypes can be made from a PM blank, also known as a slug or puck, which is manufactured so that material characteristics, such as density and chemistry, closely mirror that of the desired production component. The component geometry can be machined by traditional methods, like milling, wiring or turning, from the PM slug. In some instances, after the machining operation is completed, and depending on how aggressively the slug is machined, the component may be re-sintered to ensure that residual stresses are relieved. In some instances, after the machining operation is completed, and depending on how aggressively the slug is machined, the component may be re-sintered to ensure that residual stresses are relieved. Heat-treated or harder materials may require a pre-sintered slug so that the material is soft enough to machine, followed by a second, full sinter to reach the material's optimal physical properties. If the prototype component is to have a finish, any residual machining coolant must be removed prior to resin impregnation and/or the application of the finish.

How-To Guides

How to Select the Right Powder Metallurgy Material 

Choosing the appropriate material is crucial for successful Powder Metallurgy. Our step-by-step guide will help you make the right selection based on your project requirements.

How to Optimize Sintering Processes 

Sintering is a critical part of Powder Metallurgy. Learn how to optimize your sintering processes for improved results with our detailed guide.

How to Design for Powder Metallurgy

Effective design is key to maximizing the benefits of Powder Metallurgy. Explore our design principles and guidelines for successful projects.

Additional Resources

In addition to our FAQ and How-To Guides, be sure to explore our other resource categories:

 

Ready to dive into the world of Powder Metallurgy? 

Explore our FAQ and How-To Guides to find answers to your questions and gain valuable insights. If you have specific topics you'd like us to cover in future guides, feel free to Contact Us with your suggestions.

 

Thank you for choosing Atlas Pressed Metals as your trusted resource for Powder Metallurgy knowledge. We're here to support your journey every step of the way.

 

Need a Solution
Ask Us A Question

* Asterisk indicates a required field

contact information

Mailing Address 125 Tom Mix Dr.
P.O. Box P
DuBois, PA 15801
USA

Phone(814)-371-4800

Fax(814) 371-4182

testimonials

"Atlas presented their PM101 class to our company and it was well-received by our engineering team. They also keep us updated through their e-blasts by featuring technology advancements and process improvement announcements. Atlas has the expertise to produce a quality product and is a solid company to work with. I would not hesitate to recommend Atlas to others in the industry.”

- Michael L., VP Global Operations | Motion Technology Company