| 摘要 |
Repetitive, laser-mediated cladding is used to accumulate the build-up of material on a substrate. The apparatus and methods of use are particularly useful in fabricating metal parts through as might be required for small volume manufacturing, prototype runs, and the like. The laser is used to locally heat a spot on a substrate, forming a melt pool into which material, preferably in powder form, is fed so as to create a deposit having a physical dimension. Optical detection means coupled to an optoelectric sensor are used to monitor a physical dimension of the deposit, and a feedback controller is operative to adjust the laser in accordance with the electrical signal, thereby controlling the rate of material deposition. In the preferred embodiment, the physical dimension is the height of the deposit, and the system further includes an interface to a computer-aided design (CAD) system including a description of an article to be fabricated, enabling the feedback controller to compare the physical dimension of the deposit to the description and adjust the energy of the laser in accordance therewith. The optical detection means preferably includes an apertured mask through which light from the deposit passes to reach the optoelectric sensor, and the feedback controller includes circuitry for adjusting the laser in accordance with the presence or absence of the light from the deposit. |
