An investigation on mechanical properties of PA12 parts produced by a SLS 3D printer: An experimental approach

Abstract

Additive manufacturing methods such as Selective Laser Sintering (SLS) have attracted numerous scientists and different companies to print 3D parts. However, the mechanical properties of printed parts have been always the research area of many scientists. In this paper, the effects of SLS setting variables (laser power, scan speed, and hatch spacing) and scan length were investigated experimentally on key mechanical properties (strength, apparent modulus of elasticity, and elongation) of polyamide-12 printed parts using the response surface methodology. The results showed that the hatch spacing is the most effective variable on mechanical properties; the laser power and the scan speed are also important. By increasing the laser power and decreasing the hatch spacing and the scan speed, a higher strength part with a higher apparent modulus of elasticity and elongation can be printed. However, since a bigger hatch spacing and a faster scan speed are more desirable to have a more economical production, a challenging decision must be made for setting these variables to print parts with good mechanical behavior economically. If the hatch spacing, the laser power, and the scan speed are selected so that the laser energy density is too high, powders will burn and the printing process will fail. The scan length has a slight effect on the apparent modulus of elasticity and no significant effect on the strength and elongation. • Input variables: laser power, scan speed, hatch spacing, and scan length. • Mechanical properties: strength, modulus of elasticity, and elongation. • Effects of input variables on mechanical properties in the SLS process. • Determining effective inputs by experimental study and response surface methodology. • Predicting mechanical properties based on effective inputs and laser energy density.