3D Printing-SLM Technology

-Reprinted from 3D Printing Art Market

origin]
SLM(Selective Laser Melting) selective laser melting technology, by the German Fraunhofer Laser Institute (ILT) in 1995.

principle]
SLM uses a high-energy laser beam to completely melt the metal powder under the action of heat, and then it is cooled and solidified to form. SLM equipment is divided into lower powder feeding and upper powder feeding according to different powder feeding methods.
The powder is fed down, the powder supply cylinder rises during operation, and the powder spreading roller scrapes away the powder from the powder supply cylinder and evenly spreads a layer on the forming cylinder. The laser scans according to the cross-sectional contour of the part and selectively sinters the solid powder to form a cross-section of the part. This cycle is repeated, layer by layer, until the part is formed.
The powder is fed up, and the powder enters the powder feeding system from the powder storage device at the top of the equipment, and then enters the scraper system. When working, the scraper spreads a layer of powder first, the laser scans a layer, the forming cylinder drops a layer, the scraper returns to the origin to take the powder, and then carries out the next powder spreading after taking the powder. This cycle is repeated, layer by layer, until the part is formed.
After the parts are taken out, they need to be cleared, then heat treated to remove stress, and then the parts and the substrate are separated by wire cutting, and finally supported and polished.
[material]]
Metal powder
application]
1. Directly manufacture parts, molds, support parts, such as fixtures, fixtures, etc. Due to the high cost, it is not suitable for printing samples.
2. Titanium alloys are used in the manufacture of artificial bones.

advantages and disadvantages]
Advantages:

(1) A variety of materials can be used.

(2) The molded parts have high strength and can be directly manufactured.

(3) The material utilization rate is high, and the unsintered powder can be reused.

Disadvantages:

(1) High equipment cost, use cost and maintenance cost;

(2) high cost of printing materials;

(3) High requirements for operators and high human resource costs;

(4) The molding environment requires high requirements, requires inert gas protection, and requires preheating and cooling;

(5) The molding process produces dust and pollutes the environment;

(6) The molding surface is rough and limited by the size of the powder particles and the laser spot.

(7) Post-processing is difficult and cumbersome.