Metal material rapid prototyping technology

Knowledge sharing by Guangdong Shunde Teamwork Model Technology Co., Ltd, whom with over 20 years rapid prototyping experience.

Email: ken@gdtwmx.com

Website: www.gdtwmx.com

Rapid prototyping is a discrete/stacking process. It proposes a new thinking mode dimension model from the molding principle, that is, the three-dimensional model of the parts made on the computer is meshed and stored, and layered to obtain the two-dimensional contour information of each layer section. The contour information automatically generates a processing path, and the forming head selectively cures or cuts a layer of the forming material under the control of the control system to form each sectional profile sheet, and sequentially stacks the three-dimensional blanks in a stepwise manner. Then the blank is Post-processing to form parts.

crafting process

The process of rapid prototyping is as follows:

l) Construction of a three-dimensional model of the product. Since the RP system is directly driven by the 3D CAD model, the 3D CAD model of the workpiece being machined is first constructed. The 3D CAD model can be directly constructed using computer-aided design software (such as Pro/E, I-DEAS, Solid Works, UG, etc.), or a 2D pattern of an existing product can be converted to form a 3D model, or a product entity. Laser scanning and CT tomography are performed to obtain point cloud data, and then the reverse engineering method is used to construct the three-dimensional model.

2) Approximate processing of the three-dimensional model. Since the product often has some irregular free-form surfaces, the model should be approximated before processing to facilitate subsequent data processing. Since the STL format file format is simple and practical, it has become a quasi-standard interface file in the field of rapid prototyping. It uses a series of small triangular planes to approximate the original model. Each small triangle is described by 3 vertex coordinates and a normal vector. The size of the triangle can be selected according to the accuracy requirements. The STL file has two output forms: binary code and ASCll code. The binary code output form occupies much less space than the ASCII code output file, but the ASCII output form can be read and checked. Typical CAD software comes with the ability to convert and output STL format files.

3) Slice processing of the 3D model. According to the characteristics of the processed model, the appropriate machining direction is selected, and the approximated model is cut in a series of spaced planes in the forming height direction to extract the contour information of the section. The interval is generally 0.05mm~0.5mm, usually 0.1mm. The smaller the interval, the higher the molding accuracy, but the longer the molding time, the lower the efficiency, and the lower the accuracy, but the higher the efficiency.

4) Molding processing. According to the cross-sectional profile of the slicing process, under the control of the computer, the corresponding forming head (laser head or nozzle) performs scanning motion according to the profile information of each section, and the materials are stacked layer by layer on the workbench, and then the layers are bonded. And finally get the prototype product.

5) Post-processing of molded parts. The molded part is taken out from the molding system, polished, polished, coated, or placed in a high-temperature furnace for post-sintering to further increase its strength.