Experimental Study Of Laser Cladding Forming Of Micro-fluidic Mold

In the area of modern medicine, people have been making the micro-fluidic chip as the platform for the preparation and analysis of the biological agent instead of the traditional laboratory. Because the advantages such as space saving, widely using and carrying easily, the micro-fluidic chip already has been used in DNA analysis, gene expression analysis, disease diagnosis, drug screening and immunological test.However, the big cost of the manufacture has severely restricted its popularization. In order to cut down the Production Cycle Time and lower its' cost according to the current situation of the relative aspect, this paper has present a new technique by which the technology of laser cladding in forming the core plate of the micro-fluidic chip and the material for study is metal instead of silicon.In order to obtain the subsize workpiece in the test, a novel methods was presented which getting the ideal spot size by mask plate. The conclusions in this paper give a favor to push the development of micro-fluidic chip ahead and support certain theoretical directions for the relevant application of laser cladding. The concrete result in this paper as follows:(1) The reason for convection and its effect on the cladding layer in the molten poll were studied, as well as some interactions in the molten poll and their categories. Meanwhile, the process of laser cladding forming micro force plug is simulated by the software-ANSYS. The result of the real-time temperature on model is studied, which provides the following experiment some theoretical directions.(2) To study its character for laser cladding forming and obtain the ideal process parameters, the experiment of laser cladding forming stainless steel powder was done by JK1001 Nd: YAG pulse solid through single-factor method. According to the test result, the relationship between some process parameters and the cladding layer size, surface accuracy and microstructure was studied. Finally, the optimal parameters were obtained through orthogonal experiment: laser power: 470w, powder delivering rate: 2.0309g/min, scan rate: 500mm/min. The result of microhardness test shows the value on cladding layer is uniform distribution both along and vertical with the scanning direction, they are all proximity to that on the basic metal. The value is range between 580-590HV. As the criterion of laser cladding, the test result is receivable.(3) A new method of laser cladding forming subsize workpiece by mask plate is presented and the feasibility is theoretically proven together. The paper also points out the failure form that the mask plate may occur are bending and the reason is that the input energy density is too high. This question would be settled by control the slab thickness and the laser power, the ideal thickness is 0.2mm, finally, the micro force plug is forming by this technique.