We provide testing services to certify product and materials compliance, support quality control, and ensure the health and safety of workers and their environment. We provide assistance for clients who are not sure what tests they need. Our accredited materials characterization laboratory is the foundation of all the services of RJ Lee Group provides, including standardized testing for compliance, industrial hygiene and environmental analyses, quality control, and materials research and development.

We provide credentialed expertise supported built by robust scientific data. We provide significant support to industrial clients for product development, industrial hygiene and overall production support.

RJ Lee Group maintains a visible and respected reputation within the legal community, having offered scientific support in civil litigation matters for nearly 30 years. 

  • Product Liability 
  • Toxic Tort
  • Construction Defect
  • Fugitive Emission
  • Personal Injury
  • Patent Infringement
  • Contract Disputes
  • Insurance Subrogation

Subject Matter Experts

From our core business of providing scientific solutions to our clients, we have developed innovative products. Some are produced internally, and some have arisen from partnerships with other research organizations. 

For example, we build lab software solutions to help manage and streamline your labs data, and environmental testing products for a variety of applications. 

  • IntelliSEM is a powerful automated particle analysis system.
  • ParticleID is  a customizable cloud hosted web application used to identify foreign particulate matter and  assist with root cause investigations. 

Other products we create count particles and help keep the air and environment safe.

RJ Lee Group is a materials analysis laboratory and consulting company which serves many different industries. We offer scientific solutions such as industrial forensics services, laboratory and testing services, litigation support, and laboratory software to many industries:

Characteristics of Powder Metal for 3D Printing

Stephen Kennedy, Ph.D.

April 21, 2017

In Powder Metal (PM) applications such as 3D printing, the flow and packing behavior of PM is influenced by particle size and shape distributions. These properties can be measured in a statistically meaningful way using computer controlled scanning electron microscopy (CCSEM). In livetime, the SEM program detects a particle, defines its perimeter, calculates its size and shape properties, and saves the particle image. The shape properties quantified are elongation (aspect ratio), roundness, and form factor, as defined in ASTM F1877 Standard Practice for Characterization of Particles. All powdered metal particles in a microscope field are processed, and additional fields are processed until the stopping criterion is met. Figure 1 below shows CCSEM results of a powder sample. The shape distributions are shown for the smallest 25%, the medium 50%, and the largest 25%.

Figure 1 – An illustration of the size distribution of a sample of a powder alloy. The shape distributions can be determined on the sample as a whole, or on size fractions separately, as shown in Figures A, B, and C.

Review of the acquired images supplies a “ground truth” function to provide reality to the numeric descriptors. Figure 5 demonstrates that the Roundness value in this set of samples is primarily related to small satellites on the particle, with the size and number of fused satellites increasing with decreasing roundness. The roundness values of powder of different composition, manufactured by other techniques, or reused through multiple build cycles, may display other surface features in powdered metal.

Figure 5 – SEM images illustrating the morphological features related to the numeric value of Roundness.

These distributions can be used to compare samples, or define changes in shape with particle size. Table 1 shows the definitions of Large, Medium and Small, as well as the average values for the three shape measures. Table 1 and Figure 6 show that the smaller particles deviate from a perfect circle more than larger particles.

Table 1 – Shape distribution statistics for size fractions and the total sample.

Figure 6 – Shape Descriptor Values

Although SEM field images can be used to qualitatively assess the size and shape distribution in a general way, the CCSEM size/shape analysis can quantify shape on a particle-by-particle basis, resulting in a complete shape distribution and a deeper understanding of the powdered metal, including insight into the origin in any differences in shape. This information may be critical in understanding the flow of powder in the printer and build box, the powder-bed density, and the quality of the final product. This can be applied as a tool in assessing or qualifying virgin powder, or changes in powder that has undergone multiple build cycles.

Compositional information can also be performed with the particle-by-particle analysis using EDS. This will allow investigation of changes in powder metal composition, or the presence of extraneous particulate. The experts at RJ Lee Group can work with your team to answer questions and find solutions for your powder metal manufacturing facility. Call us today at 1.800.860.1775, ext. 4, then 2, then 1, or click on the button below to learn more.

Contact Stephen Kennedy

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