SLM: Selective Laser Melting, a rapid prototyping technology of metal powder in additive manufacturing, can directly form metal parts with close to complete density and good mechanical properties. SLM overcomes the complex process of Selective Laser Sintering (SLS) for making metal parts.
SLM: Selective laser melting
SLM technology is a kind of technology that makes use of metal powder to melt completely under the heat action of laser beam and solidify after cooling. In order to melt the metal powder completely, the laser energy density is required to exceed 106W/Cm2. At present, SLM lasers mainly include ND-YAG lasers, Co2 lasers and fiber lasers. These lasers produce laser wavelengths of 1064nm, 10640nm and 1090nm, respectively. The absorption rate of metal powder to shorter wavelength laser such as 1064nm is relatively high, but to longer wavelength laser such as 10640nm is relatively low. Therefore, in the process of forming metal parts, the laser energy utilization rate with shorter wavelength laser is high, but the laser energy utilization rate with longer wavelength Co2 laser is low.
Under the action of high laser energy density, the metal powder melts completely and can be metallurgically welded to solid metal after cooling by heat dissipation. SLM technology is a rapid prototyping technology that builds up layers of three-dimensional entities through this process.
The use of high power laser beam will be a layer of metal powder processing fusion molding, after the completion of fusion, the operating platform down a layer thickness distance, continue to process the next layer of powder, repeat this step, until the designated (selected need to be processed) all the region casting is completed, you get a three-dimensional compound. The required products (parts) are thus processed layer by layer and accumulated.