In these cases post-production process like light machining, surface finishing, or heat treatment may be applied to achieve end compliance.
Compared to processes that use powder beds, such as selective laser melting (SLM) objects created with this technology can be substantially larger, even up to several feet long.
The size and area of the melt pool and the powder plume can vary widely, and may take on spot or line configurations, depending on the target application.
The LMD process can be used in many ways, such as by scanning over a wide surface to build up a thin (< 1 mm) coating (typically called laser cladding[6][7]) or by rastering over one particular area as an additive manufacturing process to build up objects in 3D layer by layer (sometimes referred to as directed energy deposition).
This typically results in a lower portion of thermal energy being transferred into the substrate, and as a result high-speed LMD produces a thinner weld bead deposit (typically < 0.5 mm per pass[11]) with lower dilution and a thinner heat-affected zone compared to conventional LMD.
[5] The typical effect of these differences, compared to conventional LMD, is a deposit with smoother surface finish, finer grain microstructure,[13] improved corrosion resistance,[14] and higher hardness.
In Supersonic LMD a laser is used to pre-heat the substrate and the powder stream, in order to soften these materials.
[17] By avoiding melting, and by operating at a lower temperature, this reduces the chance for oxidation of the feedstock and substrate materials to occur.