Breakthrough in automated AM part density determination

View inside model ‘Additive’

Germany-based Dimensionics Density recently announced the commercial introduction of a density determination technology for additive manufacturing (AM) which contributes to the automation of the AM process chain. As AM becomes more mainstream as a production technology, the entire process chain is under intense scrutiny, but especially in the area of part validation, with finished AM parts and components now routinely used in critical end-use applications.

Philipp Pruesse, head of sales at Dimensionics Density, said: “Our technology plays straight into the need for automation in the area of validation and quality control of AM parts, and we have launched an array of tools focused on the determination of AM part density. For AM to continue to disrupt the manufacturing paradigm, the entire AM process chain needs to move towards automation.

“Because of this, our density determination solutions are fully automated, are of vital importance, and are designed to be used in production settings, not just in the laboratory. As we all know, AM stimulates design freedom as it is agnostic to part complexity. As geometric complexity increases, density determination of AM parts becomes more difficult using commonly used density determination technologies. Dimensionics Density’s solutions can easily determine the density of freeform parts and highly complex AM parts and can measure density repeatably to 0.001 g/cm³.”

Pictured right: Machine model ‘Additive’ for density cubes

The company’s density determination solution is a metrological system which has been developed for the rapid and highly accurate density determination of components, and has a particular significance when analysing AM-produced parts.

Porosity in AM parts can be a problem because it can weaken the mechanical strength and stability of the parts, reduce their durability, and make them more susceptible to failure under stress. Porosity can also affect the thermal and electrical properties of the parts and make them less resistant to high temperatures, corrosives, and other environmental factors. In addition, porosity can limit the ability of the parts to hold liquids, gases, or other materials, which can impact their performance in specific applications.

The accuracy of the Dimensionics Density system is achieved by combining the time-proven Archimedean principle with the latest automation technology and laboratory-standard precision scales.

The measuring process takes place automatically after the samples have been inserted into the universal component carriers. Numerous environmental factors that can affect the density measurement are monitored by the integrated measurement and control systems, and are taken into account when calculating the density from the measurement data. This allows accuracies to be achieved in the determination of the density, which cannot generally be realised in an industrial production environment.

Archimedes Principle
The machine uses the Archimedes Principle. The density of the test object is determined by weighing it in two different media. The first measurement is usually made in air, the second measurement in a defined liquid medium with a known density. The crucial factor for the accuracy of the result, however, is the positioning on the scale. Deviations from the centre of mass and resulting off-centre measurements of the component will lead to strong deviations. This is why the common manual Archimedes measurement solutions are not viewed favourably across industry.

Pictured left: Cube lifted from the carrier

Mr Pruesse continued: “To counteract this problem and to ensure the repeatability of the measurements, Dimensionics Density offers a universal carrier which can transport most parts, and which can be easily adapted if necessary for more complex geometries. The determined density is compared with the desired specifications, and so qualitatively more accurate assumptions can be made about the density of complex components.

“With a cycle time of less than two minutes per component and the possibility of inspecting up to 18 components simultaneously in one inspection process as standard, the Dimensionics Density solution supports the optimisation and efficiency of manufacturing processes.”

Dimensionics Density’s density determination technology is non-destructive and, therefore can be used to verify parts that conform to density requirements and those that do not in a speedy, precise, and cost-effective manner.