DMLS与SLM金属制造3D打印

3D打印正在彻底改变制造业的世界, allowing companies to produce prototypes quickly and specialized components at a relatively low cost. Most applications of 3D printing use molten plastic to produce objects in a wide variety of designs; 然而, 3D printing of metal is also emerging as a popular technique in the metal forging and fabrication industries. 

The techniques used to carry out the additive manufacture of metals are slightly different from those used to print plastics. 两种主要的技术是直接金属激光烧结和选择性激光熔化. 

直接金属激光烧结 

最有效的方法之一 加法制造 金属的激光烧结技术是直接金属激光烧结，也称为DMLS. 这个过程可以用来制造几乎任何金属合金的物体, 不像其他3D打印技术, 哪些只适用于聚合物基材料或特定的金属合金. 

Direct metal laser sintering involves spreading a very thin layer of metal powder across the surface that is to be printed. 激光缓慢而稳定地穿过表面烧结这种粉末, 也就是说金属内部的粒子融合在一起了, 即使金属没有加热到完全熔化的程度. 然后应用并烧结额外的粉末层, 这样一次“打印”一个物体的横截面. In this way, DMLS gradually builds up a 3D object through a series of very thin layers. 

一旦DMLS过程完成，打印的物体就会冷却. 多余的粉末可以从构建室中回收并循环使用. 

The major advantage of DMLS is that it produces objects free from the residual stresses and internal defects that can plague traditionally manufactured metal components. 这对于在高压力下工作的金属部件是极其重要的, 比如航空航天或汽车零部件. Traditionally manufactured metal components need to be heat-treated after they are manufactured to remove internal stresses that could cause the parts to fail. 

DMLS的主要缺点是到目前为止它非常昂贵, 这限制了它在高端应用中的使用, 例如在航空航天工业中制造金属原型零件. 然而, scientists working at Michigan Technological University have developed a 3D metal printer that costs just $1,建造500座. In comparison, most commercial metal 3D printers cost more than half a million dollars each. The printer is still very early in development; however, 这一突破可能会使DMLS技术在未来变得更便宜. 

选择性激光熔化

金属3D打印的另一种方法是选择性激光熔化(SLM)。, in which a high-powered laser fully melts each layer of metal powder rather than just sintering it. Selective laser melting produces printed objects that are extremely dense and strong. 

目前，选择性激光熔化只能用于某些金属. 该技术可用于不锈钢的增材制造, 工具钢, 钛, 钴铬合金, 铝制零件. Researchers hope that the SLM will one day be used to manufacture parts made of other metals, 但仍有一些困难需要解决. Many other metals do not have the correct flow characteristics that are needed to make them suitable for SLM. 

选择性激光熔化是一个高能量的过程, 由于每一层金属粉末都必须加热到金属的熔点以上. The high-temperature gradients that occur during SLM 制造业 can also lead to stresses and dislocations inside the final product, 这会损害它的物理性质吗. 

NASA is investigating the use of selective laser melting for the production of highly specialized parts for its spacecraft. 2013年8月, NASA issued a press release describing how it had used SLM to produce a 3D printed rocket engine injector. The 3D printed part performed successfully during a test engine firing carried out on August 22, 2013. 

NASA stated that one of the big advantages offered by SLM is that it allows workers to manufacture metal equipment as a whole, rather than having to produce individual components and assemble them to create the final product. 例如, 2013年8月测试的发动机喷油器仅由两部分组成, 与之前测试过的类似喷射器中的115个部件相比. 零件更少意味着复杂的设备更容易组装. 

The use of SLM in metal 制造业 is also being pioneered by the German company SLM Solutions. 这家公司生产工厂用的SLM机器. The company’s 3D metal printing machines are used by the industrial group Siemens to produce replacement blades for 气体 turbines. The time taken to produce a turbine blade using SLM Solutions’ 3D metal printing machines could be reduced to as little as four weeks, 而使用现有技术只需44周. 

3D打印可以显著加快金属制造的速度, reducing the amount of downtime for businesses while they wait for replacement metal parts to be created when an essential piece of equipment breaks down. This could have a domino effect of reducing delays in many different industries that use metal tools and machines to manufacture their products. 

电子束熔化 

Electron beam melting (EBM) is an 加法制造 process that is very similar to selective laser melting. 和SLM一样，它产生的模型非常密集. The difference between the two techniques is that EBM uses an electron beam rather than a laser to melt the metal powder. 

目前，电子束熔化只能用于有限数量的金属. 钛合金是该工艺的主要原料, 虽然钴铬也可以使用. 该技术主要用于制造航空航天工业的零件. 

3D金属打印的未来 

激光技术的发展, 比如飞秒激光的引入, could expand the use of 加法制造 techniques so that they can be used with a much greater range of metals and metal alloys. Femtosecond lasers are useful for 3D metal printing because they can deliver a very short pulse of high-energy laser light, 使他们能够以前所未有的精度熔合金属粉末. 

As 3D metal printing techniques continue to develop and the costs of the technology fall further, 3D打印可以在金属制造中发挥更大的作用. 3D打印技术避免了金属制造的许多典型缺陷, such as the need for post-production heat treatments and specialized machines for milling and finishing metal object. 3D metal printing could also significantly speed up production in many areas of metal 制造业.

有关直接金属激光烧结(DMLS)的更多信息, 选择性激光熔化(SLM)或电子束熔化(EBM), 请 立即im体育APP.