Rapid Prototyping: Computer-Aided Manufacturing of Laminated Engineering Materials (CAM-LEM)

这个多学科项目涉及软件、设备和材料工艺，以实现高质量的结构陶瓷部件，具有复杂的内部和外部几何形状，直接从计算机辅助设计描述中生产。该技术涉及切割和堆叠薄片以形成结构部件。通过将材料加工步骤与形状制造操作分离，该方法有望在实现整体结构完整性的同时实现高尺寸精度。通过激光切割预处理薄片，并用机器人将它们堆叠成层压组件，似乎可以实现比直接沉积技术更快的制造。此外，通过利用表面法向信息在计算切线处切割薄片，可以改善表面质量。通过切割-然后堆叠，有机会从预定的空隙中完全去除材料，以及组装易失的支撑结构。硬件问题主要集中在五轴激光切割系统的设计、构建和测试。该系统将创建具有所需轮廓和边缘切线的层。它将与一个机器人集成，用于喂料片，喂填料，去除废料，处理和组装切割薄片。机器性能问题包括实用的切割速度和可实现的切割，以及装配精度。软件开发将在两个领域整合现有知识和扩展能力。标准文件中包含的表面法线信息将用于定义锥形边缘切割的激光切割机轨迹，从而提高表面光洁度。其次，由于后处理烧制的部分收缩将建模，“绿色”部分将被预扭曲计算，以预测正确的最终尺寸。快速成型到近净形状零件在缩短周期时间，减少浪费从而降低制造成本方面为制造业提供了许多优势。该项目结合了成熟的技术，以解决目前表面光洁度和零件精度的限制。虽然该项目侧重于铸造氧化铝，但与目前快速成型工艺的小众成功相比，它具有更广泛的商业化潜力。

9420373 Newman This multidisciplinary project addresses software, equipment and materials processes for achieving high-quality, structural ceramic parts with complex interior and exterior geometries, produced directly from a computer aided design description. The technique involves cutting and stacking laminae to form a structural component. By separating the materials processing steps from the shape fabrication operations, the method promises to achieve high dimensional accuracy while achieving monolithic structural integrity. By laser slicing pre-processed laminae and robotically stacking them into laminated assemblies, it appears possible to achieve significantly faster fabrication over direct depositiol techniques. Further, by utilizing surface normal information to cut laminae at computed tangents, surface quality can be improved. By cutting-then-stacking, there is the opportunity for complete material removal from intended voids, as well as assembly of fugitive support structures. Hardware issues focus on the design, construction and testing of five axis laser- cutting system. This system will create laminae with the desired outlines and edge tangents. It will be integrated with a robot for feeding stock sheet, feeding filler material, removing waste material, and handling and assembling cut laminae. Machine performance issues include pragmatic cutting speed and achievable cutting, and assembly accuracies. Software developments will incorporate existing knowledge and extend capabilities in two areas. Surface normal information contained within standard files will be used to define laser-cutter trajectories for tapered edge cuts, thus improving surface finish. Second, part shrinkage due to post-process firing will be modelled, and "green" parts will be pre-distorted computationally to anticipate correct final dimensions. Rapid prototyping to near net shape parts offers numerous advantages to the manufacturing sector in terms of redu cing cycle time, reducing waste thus lowering manufacturing cost. This project synergetically combines well established technologies to come up with solutions to current limitations on surface finish and part accuracy. While the project focusses on cast alumina, it has the potential for much broader commercialization as opposed to the current niche successes of rapid prototyping process.