Many factors influence laser cutting quality. In this paper, the influence of laser head movement on 3D laser cutting is investigated. Except normal movement which laser head is vertical to work piece surface, three types of movement defined in 3D laser cutting are considered. Experimental design method is used to analyse cutting result. In order to quantitatively describe the relationship between cutting quality and cutting parameters, artificial neural network (ANN) has been setup. The quality marks system is used to evaluate cutting result. The test shows the calculated quality points by ANN is very similar with actual cutting result. The laser head forward movement is better than the others. The ANN is very useful to optimize cutting parameters, predict cutting result and deduce new information.
There are many micro-fabrication technologies. Some micro-components can be fabricated by selective laser sintering (SLS). When selective laser sintering metal powders is used to produce micro-components, there are numbers of factors which will influence final result, such as laser wavelength, laser power, diameter of laser beam, scanning speed, particle size and materials etc. These factors are not single but interfere with each other. The change of one factor will greatly affect the character of final micro-components (such as width of scanning track , dimension error, component hardness ,etc). In selective laser sintering metal powders, many experiments are needed in order to get the optimum process parameters. However, this will cost much time and money. Moreover in later process, new experiments will be needed in order to get the optimum process parameters due to the change of one factor. Many models about selective laser sintering metal powders have been investigated in the past. Nevertheless, these models are about the interaction of laser and metal powders, and the physical and thermal response to the initial condition. They are provided for the macro-fabrication. No model can be applied in the micro-domain, and no one aims at the influence of these factors on the character of the final micro-component. In this paper a numerical model about the relation of these factors and the character of final micro-components is provided to minimize the number of experiments. This model will include the major factors of SLS in micro-domain, and through such a model we can deduce the numerical value of optimum process parameters from final micro-component character instead of making a lot of process experiments. Therefore the cost of micro-fabrication with SLS techniques will be greatly reduced.
As laser microfabrication develops fast more and more micro parts of MEMS are produced with laser micro processing technology. Excimer laser ablation is a versatile tool for the micro machining of various materials. Excimer laser materials processing, which is performed in most cases using a mask projection system forms a 3D shape by ablation material. Recently a large number of articles about polymer ablation with excimer lasers have appeared. However the powder material especially metallic powder is paid little attention in excimer laser micro machining. In this paper several types of powder material are investigated in excimer laser ablation. The ablation rate of different powder materials with various fluence ranges, wavelengths, and pulse lengths are studied in experiment. The parameters of excimer laser were optimized to fabricate a micro part. The diameter of about 100 micron gear made of nano powder was finally produced with a mask project system using nanopowder. This method is more efficient than laser writing with a focal spot.