Harbec Explains DMLS Technology

In recent years, additive manufacturing has become a mainstream method for producing prototypes and production parts. Harbec has offered DMLS (direct metal laser sintering) and SLS (select laser sintering) services since 2000, providing customers with accurate plastic and metal prototypes.  Additive manufacturing offers many benefits over conventional machined prototypes. The typical lead time for additive prototypes is significantly less than other methods; lead times are measured in days not weeks.Direct Metal Laser Sintering DMLS

DMLS technology is a method of part manufacture that uses metal powder that is sintered using a powerful laser.  The process uses cross sectional layers at a thickness of .0007” to provide the best surface finish possible. The end result is a 100% dense metal part that is accurate within +-.002” per inch with the capability to create features as small as .007”.  The DMLS process provides engineers with part geometry options that were previously unavailable with conventional prototyping methods.  Current DMLS materials available at Harbec are:  stainless steel (17-4), maraging steel (similar to H13), and Ti64 titanium.

The SLS process is similar to the DMLS process using the same cross sectional layer method of sintering with a laser.  The major difference between the SLS and DMLS process is the medium used. SLS uses plastic powders to create durable sintered parts.  Accuracy of the SLS process is +-.01” per inch, and the process is capable of building features as small as .02”.  Current SLS materials available at Harbec: PA2200(nylon polyamide), TPE210(thermo plastic elastomer, available in a variety of durometers), Alumide(aluminum filled nylon polyamide), FR106(V0 flame retardant nylon polyamide), and  PA614-GS(40% glass filled polyamide).

DMLS/SLS comparison to conventional CNC

PROTOTYPE PARTS

DMLS/SLS

Conventional CNC

Complex Part Geometries

Single operation
(less expensive)

Multiple operations
(expensive)

Lead Times

3 – 5 days

1 – 2 weeks

Small Features

No added cost

Added cost

INJECTION MOLD CAVITIES

DMLS

Conventional CNC

Undercuts and Trapped Geometries

Possible

Not Possible

Cooling Lines

Conformal

(more efficient)

Straight only

(less efficient)

 

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