Part Generation by Layerwise Selective Sintering

该提案将研究一种新的制造工艺， 通过选择性地烧结每一层， 用激光 该过程的目标是自动生产 直接从CAD数据库中生成一般形状的三维零件 而不需要部件专用工具或人工干预。 每一层都是 对应于部件的横截面。 粉末沉积 在一个盒子里的薄层;每层沉积后，表面的 用高功率激光束对粉末进行光栅扫描。 强度 激光束的宽度被调制，使得粉末被烧结或熔融， 在该特定位置处由该部件占据的区域 横截面 在那些未烧结的区域中，粉末保持松散。 然后沉积另一层粉末并进行光栅扫描。 过程 重复进行，直到生产出整个零件。 所采用的方法是一种实验/经验方法， 结合计算机建模和分析。 的目标 建议的研究是制定一个过程模型和规则的选择 的粉末和工艺参数，并探讨后处理。 已经用塑料粉末进行了初步工作;拟议的工作 需要证明普通工程材料的可行性。 所提出的工艺是通过 光栅扫描和CAD数据库中的选择性烧结的组合 而没有部件专用工具或人工干预似乎是新颖的。 这一过程应有助于原型零件的快速生产 这将减少产品开发时间。

This proposal will investigate a new manufacturing process which builds up parts in layers from a powder by selectively sintering each layer with a laser. The objective of the process is to automatically produce three-dimensional parts of general shape directly from a CAD database without part-specific tooling or human intervention. Each layer that is built up corresponds to a cross-section of the part. Powder is deposited into a box in thin layers; after each layer is deposited, the surface of the powder is raster-scanned with a high-power laser beam. The intensity of the laser beam is modulated so that the powder is sintered or fused in the areas that are to be occupied by the part at that particular cross-section. In those areas not sintered, the powder remains loose. Another layer of powder is then deposited and raster-scanned. The process is repeated until the entire part is produced. The methodology to be used is an experimental/empirical approach used in conjunction with computer modeling and analysis. The objectives of the proposed research are to formulate a process model and rules for selection of powders and process parameters, and to explore post-treatments. Preliminary work has been conducted with plastic powder; the proposed work is needed to demonstrate feasibility with common engineering materials. The proposed process which produces a three-dimensional part by the combination of a raster scan and selective sintering from a CAD database without part specific tooling or human intervention appears to be novel. This process should facilitate the quick production of prototype parts which should reduce product development time.