Metal Laser Sintering Rapid Prototyping

It associates the latest achievements of modern digital technology, CAD / CAM technology, laser processing technology and material science. The technology uses CAD software to design three-dimensional solid model of parts. According to the specific process requirements, it completes the model slicing process in a certain thickness and makes it as a series of two-dimensional level, then the level of information on the two-dimensional data process and add processing parameters, generate NC code input machine, control machine movement at all levels in order to complete prototyping, until processed consistent with the CAD model or prototype parts. It can automatically and quickly design ideas will be transformed into a certain structure and function prototypes or direct manufacture of parts, which can carry out rapid assessment of product design, modify, in response to market demand, it does not need a lot of demand for traditional tooling methods mold, save cost and shorten the processing manganese powder cycle, to achieve high efficiency, low consumption and intelligent purpose.

Rapid prototyping technology was originally used to make foundry model was developed to manufacture prototype parts, mainly used for model or part of the visual inspection, the key is to ask the exact shape, its mechanical properties is not too high, as required by the use of the molding material liquid photosensitive resin, wax, paper, alternative materials. In recent years, rapid prototyping technology, a new development, has begun to metals, ceramic materials are applied on the preparation, the main goal is to quickly produce to meet the performance of the dense metal parts.

Metal powder sintering technology is currently a hot international field of study, you can automatically quickly directly from 3D CAD models obtained by the shape of complex metal parts or model, its manufacturing methods include selective laser sintering (SLS) and laser cladding manufacturing two techniques.

Selective laser sintering is the use of selective laser sintered powder layer, and to sintering of the solidified layer, layer stack to generate the required shape of the parts. First produced by the CAD part model, and use slicing software to process it, to obtain information on the shape of the cross-section parameters, as two-dimensional scanning of the laser beam path, the beam emitted by the laser control of the computer, according to the geometry of the layer cross-section of the coordinate data to selectively scan the material powder layer, the laser irradiation position in the powder sintered together, a layer of sintering is complete, the next layer of scanning holes and sintered powder, a new layer and the previous layer naturally sintered together, the resulting three-dimensional shape of the parts.

Compared with other traditional manufacturing methods, selective laser sintering technology advantage is: ` high degree of flexibility, under the control of the computer can quickly and easily create traditional processing methods are difficult to implement parts of complex shapes, such as with complex concave and convex parts and hollow parts. a technology is highly integrated, comprehensive integration of computer technology, CNC technology, laser technology and materials technology. b short production cycle, from CAD design to the technical parts of the process just a few hours to several hours to complete, especially for the development of new products.

General SLS RPT is the output of CO2 laser beam through the focusing lens to form the work surface with high energy density and the size of a small spot, this spot in the table on the paving material for sintering boron powder, and change line-scanning SLS RPT is the laser beam through the cylindrical lens on the table to form a spot with the same energy density of the thin wire with forming large size, forming efficiency advantages. And the metal powder selective laser sintering technology quickly and only in the North University of China conducted a series of studies, and molded parts for post-processing such as infiltration of copper, high temperature sintering process was studied, and achieved remarkable results.

Laser rapid prototyping of metal powder set of computer-aided design technology, laser cladding, rapid prototyping in one, without any hard work in the mold or model in the case, different materials can be quickly prepared the complex shapes, multi-species, small quantities of parts, forming part of the high density, fast solidification characteristics, to meet the direct requirements in aerospace components, aircraft engine parts and weapons on the part of the preparation has broad application prospects. Also by changing the molding material, to be composed of different materials in different parts of parts, combined with the computer, the development of smart materials preparation system.

At present, the rapid prototyping technology forming accuracy of 0.01mm magnitude, surface quality is also poor, to be further improved. Most important is the strength and toughness of the molded part can not fully meet the practical needs of engineering, rapid prototyping process and improve the existing equipment, improve molding precision parts, strength and toughness and reduces operating costs is very urgent.

Rapid prototyping as a high-tech manufacturing technology will constantly develop new molding process, molding materials and intelligent technologies based on the rapid developments in the past ten years. The existing processes will also go towards the direction of precision, high- precision, low-cost, standardized and should be able to produce semi-functional, functional parts. Source: http://www.mhcmp.com