Designing a Tool System for Lowering Friction during the Ejection of In-Die Sintered Micro Gears

The continuous improvements in micro-forging technologies generally involve process, material, and tool design. The field assisted sintering technique (FAST) is a process that makes possible the manufacture of near-net-shape components in a closed-die setup. However, the final part quality is affected by the influence of friction during the ejection phase, caused by radial expansion of the compacted and sintered powder. This paper presents the development of a pre-stressed tool system for the manufacture of micro gears made of aluminum. By using the hot isostatic pressing (HIP) sintering process and different combinations of process parameters, the designed tool system was compared to a similar tool system designed without a pre-stressing strategy. The comparison between the two tool systems was based on the ejection force and part fidelity. The ejection force was measured during the tests, while the part fidelity was documented using an optical microscope and computed tomography in order to obtain a multi-scale characterization. The results showed that the use of pre-stress reduced the porosity in the gear by 40% and improved the dimensional fidelity by more than 75% compared to gears produced without pre-stress

Adjustable broaching tool for tolerance compensation in precision manufacturing

Current manufacturing of precision tools for machining typically requires processes such as grinding, EDM or laser processing in order to comply with high requirements on tolerances. However even tools manufactured by these processes come short, when a new batch of workpieces are supplied, and their tolerances are not compliant. This approach presents a precision broaching tool for adjusting the inner diameter of an external broach. The tool compensates for the manufacturing tolerance chain of tool and workpieces by up to 37 μm. The approach is based on conventional shrink fitting of cold forging tools. A numerical and analytical model of the compression is compared with experimental results

A Water Treatment Case Study for Quantifying Model Performance with Multilevel Flow Modeling

Decision support systems are a key focus of research on developing control rooms to aid operators in making reliable decisions and reducing incidents caused by human errors. For this purpose, models of complex systems can be developed to diagnose causes or consequences for specific alarms. Models applied in safety systems of complex and safety-critical systems require rigorous and reliable model building and testing. Multilevel flow modeling is a qualitative and discrete method for diagnosing faults and has previously only been validated by subjective and qualitative means. To ensure reliability during operation, this work aims to synthesize a procedure to measure model performance according to diagnostic requirements. A simple procedure is proposed for validating and evaluating the concept of multilevel flow modeling. For this purpose, expert statements, dynamic process simulations, and pilot plant experiments are used for validation of simple multilevel flow modeling models of a hydrocyclone unit for oil removal from produced water. Keywords: Fault Diagnosis, Model Validation, Multilevel Flow Modeling, Produced Water Treatmen