Modelling, simulation and validation of CMT process: an application for additive manufacturing
Välimäki, Emmi (2017)
2017
Materiaalitekniikka
Teknisten tieteiden tiedekunta - Faculty of Engineering Sciences
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Hyväksymispäivämäärä
2017-03-08
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201703091141
https://urn.fi/URN:NBN:fi:tty-201703091141
Tiivistelmä
Traditional welding, among the many other processes has been given promise to the additive manufacturing industries. Creating models to predict the quality of the manufactured part can be highly beneficial and can create useful knowledge of the process and material. In this thesis, a cold metal transfer (CMT) technology was modelled for single bead using dimensional analysis conceptual modelling (DACM). DACM is a method that supports the production of model. The method can be used different ways and in this thesis, two of the ways are presented, with the use of already known theory and without the knowledge. Method uses several different modelling methods, such as dimensional analysis, bond graph theory and causality rules.
CMT technology is an arc welding method. It differs from the typical welding method in such a way that the wire feed pulls in causing the droplet to detach. This movement can happen between 50-130 Hz and it reduces the heat input to the substrate material. Since the CMT is a highly-controlled system it has some parameters that are not know by user. These parameters were clarified during this thesis. Simple regression model was created to understand how the parameters affect. Materials in use was aluminium alloy AlSi5 and stainless steel 316L.
Creation of the regression model was carried out with Taguchi design of experiments (DoE). Results were analysed by analysis of variance (ANOVA) and a nonlinear regression was created to understand how CMT parameters affect. Full model, created by the regression and by the DACM method, was validated. It was able to predict values that were close to the actual values but not in the acceptable level. The model should be developed in order to gain more accuracy. It was noted that some factors were missing in the model and should be integrated to the model in future studies.
CMT technology is an arc welding method. It differs from the typical welding method in such a way that the wire feed pulls in causing the droplet to detach. This movement can happen between 50-130 Hz and it reduces the heat input to the substrate material. Since the CMT is a highly-controlled system it has some parameters that are not know by user. These parameters were clarified during this thesis. Simple regression model was created to understand how the parameters affect. Materials in use was aluminium alloy AlSi5 and stainless steel 316L.
Creation of the regression model was carried out with Taguchi design of experiments (DoE). Results were analysed by analysis of variance (ANOVA) and a nonlinear regression was created to understand how CMT parameters affect. Full model, created by the regression and by the DACM method, was validated. It was able to predict values that were close to the actual values but not in the acceptable level. The model should be developed in order to gain more accuracy. It was noted that some factors were missing in the model and should be integrated to the model in future studies.