Product Design, Manufacturing, and Materials

Posted by Michael Pfeifer, Ph.D., P.E.

Designing and manufacturing a mechanical, electrical, or electromechanical device requires thorough specification of the materials properties of the individual components and controlling the materials properties. Doing these will help ensure high manufacturing yields, good quality, and good reliability.

For some products the materials requirements are minimal, allowing for a wide range of material variation in order to produce the final product. Other products with many materials requirements (e.g. automotive, medical, appliances) require tight control of the materials properties.

There are many opportunities during the course of designing a product to get information about the materials properties, how tightly they must be controlled, and the ability of suppliers to maintain the required control. These include:

  • Perform a literature review to determine if the materials have been used in a similar application, how the materials are expected to degrade, and the expected reliability of the materials.
  • For materials such as adhesives, solder paste, coatings, etc. recognize that supplier materials properties data is probably nominal. However, all materials’ properties have some degree of variation. Have the materials properties analyzed (use at least 3 separate production lots) to determine the expected variations. Use this information to help write the materials specifications. Also, use the same 3 lots of material for process development. Keep data on the development yields vs. materials properties.
  • For custom made components (e.g. castings, moldings, stampings) get samples of similar parts that were made by the supplier. Have some of the basic materials properties of the parts analyzed to determine the supplier’s ablility to make the components to the required specs and to get an idea of the expected variation. A little bit of money spent on this at the beginning of a program can have a huge payback, especially if it is determined early in the program that the supplier is not capable.
  • Characterize materials interactions by performing accelerated life tests on a sub-set of components. This should be done in parallel with the other design efforts. The information will enable the design team to assess the expected reliability without having to build the entire product, giving the team a chance to test more than one material at a time. It will also provide data for specific materials and components that can be used in future supplier, quality, performance, and cost reduction efforts.
  • Evaluate the materials properties before and after product validation testing to have a correlation between materials properties, degradation, and performance. This information may also be useful at a later date if there are problems with supplier or product quality.
  • Review the design with a materials engineer to detemine if better materials options exist.
  • Write thorough materials specifications for all the components and materials used in the product.

All these items can be done in parallel with the typical mechanical design effort. The companies that are successful at taking avdantage of these opportunites will find it easier to meet project deadlines and encounter fewer surprises. The others will have opportunities to work on failure analyses, spend time on daily conference calls with frustrated customers, and figure out if they supplier or internal manufacturing problems.

About Michael Pfeifer, Ph.D., P.E.

Michael is Principal Engineer and Trainer at Industrial Metallurgists, LLC. Reach him at mike@imetllc.com or 847.528.3467