Automated instead of manual: Quality leap in the determination of the powder metallurgical density of green compacts
Quality assurance is crucial in powder metallurgy. However, with the usual manual methods for determining density, numerous sources of error can falsify the result. With the DIMENSIONICS DENSITY scale, Dimensionics has launched a metrological system that prevents erroneous measurements and enables the density of a wide variety of components within a manufacturing environment to be determined quickly and highly accurately.
Prefabricated parts made of metal powders are used in many places in industry because they are characterised by high dimensional accuracy and a wide density spectrum. For production, the base materials are pressed into their shape and the green compact is then finalised by thermal treatment, known as sintering. The homogeneity of the component is crucial for its quality.
Therefore, the density is an important criterion for the quality of sintered workpieces. It provides information about possible structural defects, such as inclusions or cracks. Qualitative testing of the products with regard to their density properties is essential.
Challenges in determining powder metallurgical density
The components are currently being tested in laboratories. So-called density kits are often used for this purpose, which are similar to a Jolly balance in their construction and basic principle. They rely on the proven Archimedean principle, which states that “the static buoyancy of a body in a medium is equal to the weight force of the medium displaced by the body.” It follows that the density of a body can be determined by its mass determination in air as well as in a liquid medium.
For such a density determination, the components have to be pre-treated, which is time-consuming and ties up personnel resources. One reason it is so time-consuming is the preparation of the samples, as this is sometimes not non-destructive, insofar as the body has to be cut up (segmented) and prepared for random sample examinations. However, despite the effort involved, density determination using density kits is currently the most common way of examining the density of components in industry.
Factors influencing the precision and accuracy
The quality of the results in this procedure depends on a variety of factors. On the one hand, there are external influences such as temperature fluctuations, humidity or vibrations introduced into the system. On the other hand, there is also a not-inconsiderable human influence. Since several people are usually involved in the process of density determination, this factor plays a crucial role and prevents the process from being exactly reproducible. This poses a major challenge for the traceability of production – and thus for the overall reliability of the process. In order to minimise these risks and reduce the time required for a test, Dimensionics has developed the first fully automated system for density determination, the DIMENSIONICS DENSITY scale. Its unique concept allows it to inspect components precisely, quickly and with repeatable accuracy with regard to their density – right on the shop floor.
Measurement system eliminates disruptions
The metrological system of the DIMENSIONICS DENSITY has a closed measuring cell and enables it to be used in an environment close to where the production process is taking place. This takes the pressure off the laboratory and considerably reduces times when the machine is down.
In addition, the quality of results also improves massively. Inside the cell, the installed measurement technology ensures that the environmental parameters are recorded and processed. All influencing factors are taken into account when the results are determined by the algorithm developed by Dimensionics. An innovative handling system developed for positioning and transporting the components guarantees high repeatability of the system.
Precise work area safety guidance for high process accuracy
The system offers space for 15 different types of components as standard, which can be inspected fully automatically. High-precision laboratory trolleys from a renowned company in the field of laboratory technology are installed for the highly accurate determination of mass, the basis of the determination of density. Together with the handling system, the system can achieve precision and accuracy of up to ± 0.001 g/cm³.
The measurement of a sample takes less than three minutes. The results are processed and prepared for the worker automatically. Data can be exchanged via communication interfaces to higher-level ERP systems and results can be transferred to the internal system automatically.
The DIMENSIONICS DENSITY can be easily integrated into existing process structures. With fast and repeatable density determination in a near-production environment, it provides an ideal solution for streamlining and optimising existing processes. The elimination of human factors also makes the manufacturing process more reproducible and makes the company’s processes more reliable.
Contact us
Feel free to contact us directly for further advice or questions! Also make use of the option to send us some density cubes to be measured with the DIMENSIONICS DENSITY! We will be happy to help you and get back to you immediately.
info@dichtewaage.de Phone +49 38208 821705
Simply download our DIMENSIONICS DENSITY product brochure.
