Grant: Research Tools and Instruments - Category 1 (<$150,000)

Near-net-shape processes are alternative methods of manufacturing products which provide minimal raw material wastage and little need for secondary machining or finishing. Powder metallurgy (PM) technologies are some of the most popular near-net-shape processes, where powdered metals are pressed into complex product geometries. Using the popular 'press-and-sinter' production process, powdered metal is pressed (compacted) in a die to the desired shape. These 'green compacts' are then heated in a controlled environment (sintered). Sintering sets the part microstructure and heavily influences its mechanical properties. However, after each of these processes the part often exhibits dimensional changes which, given the primary attractiveness of PM technologies, greatly lowers part quality. Two principal dimensional changes are springback and warping. After compaction, the part slightly enlarges as the powder relaxes, which is known as springback, and after sintering the part often warps or distorts considerably. The PM research group at Dalhousie is actively investigating both springback and warping with particular focus on modifying powder constituents and process parameters to mitigate these dimensional changes. These very small changes (~300 µm) are difficult to measure experimentally but are critical to the ongoing research. The proposed equipment, an automated 3D laser scanner, rotates a part and scans it vertically with a high precision laser to measure the surface geometry. By comparing the measured geometry to CAD models of the desired shape the springback and warping can be quantified to within 7 µm. The proposed equipment will help researchers develop new compaction techniques and sintering methods which minimize springback and warping. In addition, it will give researchers the capability to assess and predict dimensional changes for novel PM alloys. These capabilities would be unique in Canada, both in academic and industrial operations.