Improvement of part surface finishing in laser sintering by experimental design optimisation (DOE)
The purpose of this experiment was to improve the surface quality of part produced by Laser Sintering (LS) and to reduce or eliminate the rough surface texture known as 'Orange Peel' by optimising the LS process parameters. The 2500 HiQ 3D system was employed in the experiment. The laser scan speed, scan spacing, laser power, scanning strategy, and part bed temperature were chosen as factors. The fractional factorial of design of experiment (DOE) at half five factors () with two levels were experimentally tested. The Melt Flow Rate (MFR) was selected to determine the recycled powder quality. Recycled PA2200 powder with 18-19 MFR was used in the experiments. The score system was introduced to evaluate the response variable. The 'orange peel' surface texture is influenced by the variable scan spacing (SCSP), as well as by interactions between laser power (LP) and laser scan speed (LSp); laser power (LP) and scanning strategy (SSt); and laser scan speed (LSp) and scan spacing (SCSP) are significant. This methodology could be used to find out the optimum LS process parameters setup in relation to the recycled powder PA2200 properties and best surface quality of the LS part.
Dear Mr.Mahmud
Many thanks for reading my paper. For your information the term "Experimental Design" also well known as "Design of Experiment". Therefore someone can uses abbreviation DOE or ED. You could find the application of these both terms (ED and DOE) in many paper publications, statistics books and quality design books.
If you refer to my paper, the 18-19MFR powder quality stated that it is twice used powder which cause "orange peel" texture on the sintered part. In the real laser sintering practice, this 18-19MFR power quality grade is discard. In order to reduce the manufacturing cost, saving the energy and environmental issue, an attemped to use the experimental design approach has been done. The reason is laser sintering part quality is not only depend on the powder quality but also significantly influence by its process parameter.
Thank your for the interesting paper. My question is that
Can you find the correlation from the analysis result between two types of SLS materials (15-16 and 18-19 MPR powder)?
The correlation mentioned here is about the factors that influences in responsive variable (scan spacing, laser power, scanning strategy, laser scanning speed and part bed temperature).
Many thanks,
Le
Many thanks for the question.
In the real laser sintering practice, these both powders (15-16MFR & 18-19MFR)were throw away due to badly deteriorated which causes orange peel texture problem. According to DOE analysis, the “orange peel” surface texture is influenced by the variable scan spacing (SCSP), as well as interactions between laser power (LP) and laser scan speed (LSp); laser power (LP) and scanning strategy (SSt); and laser scan speed (LSp) and scan spacing (SCSP) are significant. The optimisation process parameters sucessfully eliminate orange peel texture problem only on 18-19MFR powder, however this problem unable be solved when it was applied on 15-16MFR powder.This could be due to the thermal properties of 15-16MFR was very badly deteriorated at molecule level which could not be improved the sintering mechanism during LS process.
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- Gregor Mroz
i read your paper it is nice paper, but in your title your wrote experimemtal design means (ED) and you wrote (DOE) D- design and E experiments and what is the latter O means here.
i think you should refer to your previuos wrok to explain why you selected 18-19 MFR