Laser measurement of dimensional change sin powder metallurgy manufacturing processes

近净成形工艺是制造产品的替代方法，它提供最小的原材料浪费和很少需要二次加工或精加工。粉末冶金（PM）技术是一些最流行的近净成形工艺，其中粉末金属被压制成复杂的产品几何形状。使用流行的“压制和烧结”生产工艺，粉末金属在模具中被压制（压实）成所需的形状。然后在受控环境中加热这些“绿色致密物”（烧结）。烧结决定了零件的显微组织，严重影响了零件的力学性能。然而，在每一个这些过程之后，零件经常表现出尺寸变化，考虑到PM技术的主要吸引力，这大大降低了零件质量。两个主要的维度变化是回弹和翘曲。压实后，由于粉末松弛，零件略有扩大，这被称为回弹，烧结后零件经常翘曲或扭曲相当大。

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.