Metallurgy Posts

A stainless steel tool chuck was cracking during product assembly, affecting about 30% of all chuck. A failure analysis of the cracked chucks and analysis of the chuck design and manufacturing process was performed to determine the root cause of the cracking. This article discusses the findings and how the problem could have been prevented.

A failure analysis is performed on metal objects that stop performing as required or fail to meet quality requirements. This video is a short discussion of the circumstances when a failure analysis is performed, the goals of a failure analysis, and the steps of a failure analysis.

An engineered product is a collection of materials in the shapes of components and weld, solder, or adhesive joints. In fact, up to 70% of the cost to make a product is due to its materials. Therefore, it makes sense that getting the materials right will have a big impact on a product’s success. However, many organizations have difficulties getting the materials right, and they end up facing common problems such as:

During our March 19, 2015 metallurgy question and answer webinar I answered the following question: What is needed to meet specs for solution treated and aged 7175 aluminum? This video recording shows my reply.

During product development of a power tool, the material to use for a drive shaft was being considered. Based on the requirements for the drive shaft an aluminum alloy was identified as a potential candidate. Evaluations were performed to to determine whether the alloy was suitable. Also supplier evaluations were conducted to identify a capable supplier of drive shafts once the product went into production. This case study discusses the evaluations and their results.

Formability refers to the ability of sheet metal to be formed into a desired shape without necking or cracking. Necking is localized thinning of the metal that is greater than the thinning of the surrounding metal. Necking precedes cracking.

From the metallurgical perspective, the formability of a particular metal depends on the metal’s elongation, which is the total amount of strain measured during tensile testing.

Whether you are through hardening steel, annealing a cold-worked metal, or solution treating an aluminum alloy, the heat treating temperature is critical for obtaining the desired microstructure, and therefore, the desired metal properties. Using a temperature that is too hot can result in a metallurgical transformation that proceeds too quickly or the formation of undesired phases. Using a temperature that is too low can result in incomplete metallurgical transformations, cold worked metals that do not soften sufficiently, or insufficient stress relief.

Rockwell and Brinell hardness tests are common metal characterization methods used to determine whether metal stock or a metal component has the required properties. The reason for this is that these tests are simple and quick to perform, in addition to being inexpensive. However, while these tests do provide useful information, there is a danger to the common practice of specifying only hardness and alloy composition on component design drawings.

One approach to cost reduction is to re-engineer products to use less expensive materials or reduced quantities of higher priced materials. This approach can have a significant impact on a product’s costs, since the materials used in a product account for a large part of its total cost. With appropriate design verification, it is possible to make the desired product changes and preserve the required performance and reliability. In fact, sometimes a product’s performance and reliability is also improved, providing an additional competitive advantage.

OEMs and Tier 1 manufacturers are moving business to global low-cost suppliers. As a result, U.S. stampers try to remain competitive by cutting costs or offering more services. U.S. stampers are missing an opportunity to gain a competitive edge by offering materials engineering support that the OEMs and Tier 1 suppliers often lack. Instead, many stampers take the position that they just build to a print—but so do overseas shops. So how will U.S. stampers differentiate themselves?

This article outlines an eight-step process to help you identify and repair the root cause of a problem that arises when working with suppliers.

I have consulted with manufacturers in many industries. Regardless of the products being produced, they all face the same general challenges and frustrations about product development and manufacturing. Each of them is concerned about the following questions that impact their profitability:

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.

Suppliers of components and sub-assemblies are critical to the success of most companies. Companies depend on their suppliers to provide an item that always satisfies its design requirements and is always delivered on time. However, companies do not always use a methodical approach for evaluating and selecting suppliers. Instead, they are lured by the promise of a low piece part price, only to find that the costs due to poor quality and delayed product launch quickly overshadow the planned savings. This article explains how to select suppliers that will enable production at the lowest total cost and highest quality.

Suppliers of components and sub-assemblies are critical to the success of a product. This is the second part of a two-part article that discusses the considerations for selecting suppliers that will enable production at the lowest total cost and highest quality. The first article discussed the materials engineering and supply chain perspectives that must be considered when evaluating and selecting suppliers, and ended with a list of supplier selection criteria. This article explains the considerations for each of the selection criteria and discusses the evaluation process.

The strength of metals is improved by impeding the motion of dislocations through the metals. One approach to achieving this improvement is to form a uniform distribution of closely spaced sub-micron sized particles throughout an alloy. The particles, called precipitates, impede dislocation motion through the alloy. Not every alloy can be precipitation strengthened. Alloys that can be precipitation strengthened include Al-Cu, Al-Mg-Si, Cu-Be, and 17-8 PH steel.