Technology of metallic 3D Printing is analytic how to reduce leftover stress

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  • source:BREDA CNC Machining
The like a raging fire that metallic 3D Printing develops in last few years, had been applied gradually all trades and professions: Aerospace, car, medical treatment is waited a moment. Its advantage depends on can accomplishing a spare parts light quantify individuation to design, can solve a few traditions to machine the technical difficult problem that production means cannot accomplish, come to those who say can exist in 3D Printing process from technical level however a lot of problems make our design cannot according to expect be printed to come out, have the following reason: Leftover stress, the spare parts is put, prop up, the spare parts is optimized etc. So we introduce the effect that leftover stress causes to process of metallic 3D Printing and us how to should avoid in detail today! Leftover stress: Leftover stress is the inevitable result that heat quickly and cools, this is laser powder bed the inherent character of fused craft. Each new treatment layer builds through following means compose: In laser of focusing of the shift on pulverous bed, fused powder carries a layer on the head and the fusion of layer of a treatment its and lower part. The quantity of heat in hot bath can deliver the solid metal to lower part, the metal of such melt can cool and caky. This one procedure is very quick, have a few small seconds only about. New metallic layer is in of lower level metal on the surface is caky appear with the meeting when refrigeration contractive phenomenon, but because get the limitation of structure of lower part solid, its systole can be brought about shearing force is formed between layer and layer. Laser forms new solder to in the coping melt metal of solid matrix (left) . Laser moves along scanning vector and melt is pulverous, come through delivering quantity of heat subsequently the solid metal of lower part, the powder after melt begins to cool. Caky hind, cooling metal is contractive, this metal layer and below one shearing force can be formed between the layer (right) rudimental stress is had ruinous. A coping is machined to increase another treatment in when us when the layer, stress is formed subsequently and accumulate, this may bring about a spare parts to be out of shape, its brim furls, may break away from later prop up, the outside leaves in the spare parts bigger and below the circumstance of joint substrate, spare parts brim can break away from substrate: Below the situation that compares an extreme, stress may exceed the intensity of the spare parts, create package ruinous craze or substrate are out of shape: These cases appear in commonly bigger in sectional spare parts, because the interface is too big the distance that causes shearing force effect is longer, bring about a spare parts to be out of shape thereby or substrate is out of shape. Optimize a design to be planted to this circumstance, the issue of stress considers when we should be being designed above all, optimize a design namely, as far as possible go avoiding bedding face to accumulate uninterrupted agglomeration. Choose a few thicker substrate as far as possible, substrate heats also is to be able to ease this kind of problem, print data of 316L stainless steel for example of major manufacturer heat temperature is 80 Celsius. When changing scanning means to use powder of metal of upper part of laser agglomeration substrate when us, laser can be mixed along certain way and geometrical appearance comes fill spare parts. Normally this process can move back and forth laser, this process is called scanning. Scanning means has a lot of kinds, for example stripe scanning, helix of inside and outside scans, tilt divisional scanning. With tilting divisional scanning is exemple, this kind of scanning also is the scanning means when major part is printed. We can pass the scanning way that changes laser to reduce the leftover stress on the spare parts, machining the direction that scanning vector rotates when the layer moves to machine a layer to the next from, come so, stress won't be entirely on same plane concentration, every rotate normally between the layer 67 degrees, repeat completely in order to ensure after machining a lot of layers scanning direction just is met. Above is a few commonly used methods that improve stress remain, but these methods are applied to only will improve in printed process, and optimal program is the problem that in designing a process, remains considering stress avoids thereby. (author: The tribe of 3) CNC Milling CNC Machining