The amount of radiated energy is known to be a crucial parameter in powder-bed additive manufacturing (AM) processes. The role of irradiance in the multijet fusion (MJF) process has not been addressed by any previous research, despite the key role of this process in the AM industry. The aim of this paper is to explore the relationship between irradiance and dimensional accuracy in MJF.
An experimental activity was carried out to map the relationship between irradiance and dimensional accuracy in the MJF transformation of polyamide 12. Two specimens were used to measure the dimensional accuracy on medium and small sizes. The experiment was run using six different levels of irradiance. For each, the crystallinity degree and part density were measured.
Irradiance was found to be directly proportional to part density and inversely proportional to crystallinity degree. Higher irradiance leads to an increase in the measured dimensions of parts. This highlights a predominant role of the crystallisation degree and uncontrolled peripherical sintering, in line with the previous literature on other powder-bed AM processes. The results demonstrate that different trends can be observed according to the range of sizes.
The authors would like to thank the MIUR (Italian Ministry of University and Research) for funding support and Juno Design S.r.l. for laboratory facilities. Raw experimental data are available on request. Please contact the corresponding author.
Data Availability: The benchmark part used to evaluate accuracy on medium sizes is made available for download by HP at: https://support.hp.com/us-en/drivers/selfservice/hp-jet-fusion-3d-4200-printer/11461058
The STL file of the benchmark used to measure small dimensions can be downloaded at: https://osf.io/trn5b
Mele, M., Campana, G. and Monti, G.L. (2021), "On the effect of irradiance on dimensional accuracy in multijet fusion additive manufacturing", Rapid Prototyping Journal, Vol. 27 No. 6, pp. 1138-1147. https://doi.org/10.1108/RPJ-07-2020-0180
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