New particle size measurement technique uses air permeability for greater precision

News
August 23, 2017

August 23, 2017

New particle size measurement technique uses air permeability for greater precision

The Subsieve AutoSizer (Courtesy Micromeritics Instrument Corporation)

 

Micromeritics Instrument Corporation’s Particulate Systems Division, Norcoss, Georgia, USA, has announced a new instrument for the more precise estimation of the average particle size of powders. The new instrument uses an air permeability technique previously popularised by the Fisher Sub-Sieve Sizer, which is no longer available.

The Subsieve AutoSizer (SAS) measures the specific surface area of a powder by passing air through a packed powder bed and determining the pressure of the transmitted air by means of calibrated and traceable digital pressure transducers (also used for setting the packing force and input pressure) instead of the water-filled manometer standpipe (or bubble-rate pressure estimate, in the case input pressure) used in older methods. The specific surface area is then easily converted by the instrument to an equivalent spherical particle diameter using geometric and density considerations.

For over fifty years, the refractory metals, ceramics, lighting, other phosphors and pharmaceutical industries have relied on air permeability measurements to estimate the particle size of their materials. Some of these methods offer very imprecise results, leading to a large degree of rework and confusion in those industries. Because of its accurate and precise measurement of pressure by means of pressure transducers, the SAS reportedly provides much greater precision than traditional methods, allowing for appropriate particle size specifications to be set for both process and quality control, and for outgoing powder material specifications. The new instrument thus offers a fast and easily-obtained estimate of particle size in order to meet those specifications.

Several international standard test methods have been developed for use with the SAS, including ASTM Standard Test Methods B330 (for metals), C721 (for some ceramic materials) and E2980 (a general standard for particle size measurement of a wide range of materials). ISO Standard 10070, a general standard test method for this type of particle size measurement, is currently being revised for use with the SAS.

www.micromeritics.com

News
August 23, 2017

In the latest issue of Metal AM magazine

Download PDF
 

Extensive AM industry news coverage, as well as the following exclusive deep-dive articles:

  • Metal powders in Additive Manufacturing: An exploration of sustainable production, usage and recycling
  • Inside Wayland Additive: How innovation in electron beam PBF is opening new markets for AM
  • An end-to-end production case study: Leveraging data-driven machine learning and autonomous process control in AM
  • Consolidation, competition, and the cost of certification: Insight from New York’s AM Strategies 2024
  • Scandium’s impact on the Additive Manufacturing of aluminium alloys
  • AM for medical implants: An analysis of the impact of powder reuse in Powder Bed Fusion

The world of metal AM to your inbox

Don't miss any new issue of Metal AM magazine, and get the latest industry news. Sign up to our twice weekly newsletter.

Sign up

Discover our magazine archive…

The free to access Metal Additive Manufacturing magazine archive offers unparalleled insight into the world of metal Additive Manufacturing from a commercial and technological perspective through:

  • Reports on visits to leading metal AM part manufacturers and industry suppliers
  • Articles on technology and application trends
  • Information on materials developments
  • Reviews of key technical presentations from the international conference circuit
  • International industry news

All past issues are available to download as free PDFs or view in your browser.

Browse the archive

Looking for AM machines, metal powders or part manufacturing services?

Discover suppliers of these and more in our comprehensive advertisers’ index and buyer’s guide, available in the back of Metal AM magazine.

  • AM machines
  • Process monitoring & calibration
  • Heat treatment & sintering
  • HIP systems & services
  • Pre- & post-processing technology
  • Powders, powder production and analysis
  • Part manufacturers
  • Consulting, training & market data
View online
Share via
Copy link
Powered by Social Snap