Pascu Sergiu

Mr. Pascu Sergiu


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 August 2023 in Polymers
Verified
Journal Article
Open access
PDF file
PSPascu Sergiu
Pascu Sergiu
Nicolae BalcNicolae Balc
Nicolae Balc
This paper presents a new method of process parameter optimization, adequate for 3D printing of PLA (Polylactic Acid) components. The authors developed a new piece of Hybrid Manufacturing Equipment (HME), suitable for producing complex parts made from a biodegradable thermoplastic polymer, to promote environmental sustainability. Our new HME equipment produces PLA parts by both additive and subtractive techniques, with the aim of obtaining accurate PLA components with good surface quality. A design of experiments has been applied for optimization purposes. The following manufacturing parameters were analyzed: rotation of the spindle, cutting depth, feed rate, layer thickness, nozzle speed, and surface roughness. Linear regression models and neural network models were developed to improve and predict the surface roughness of the manufactured parts. A new test part was designed and manufactured from PLA to validate the new mathematical models, which can now be applied for producing complex parts made from polymer materials. The neural network modeling (NNM) allowed us to obtain much better precision in predicting the final surface roughness (Ra), as compared to the conventional linear regression models (LNM). Based on these modelling methods, the authors developed a practical methodology to optimize the process parameters in order to improve the surface quality of the 3D-printed components and to predict the actual roughness values. The main advantages of the results proposed for hybrid manufacturing using polymer materials like PLA are the optimized process parameters for both 3D printing and milling. A case study has been undertaken by the authors, who designed a specific test part for their new hybrid manufacturing equipment (HME), in order to test the new methodology of optimizing the process parameters, to validate the capability of the new HME. At the same time, this new methodology could be replicated by other researchers and is useful as a guideline on how to optimize the process parameters for newly developed equipment. The innovative approach holds potential for widespread equipment functionality enhancement among other users.

3 August 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
PSPascu Sergiu
Pascu Sergiu
NBNicolae Balc
Nicolae Balc
This paper presents a new method of process parameters optimization, adequate for 3D printing of PLA (Polylactic Acid) components. The authors developed a new Hybrid Manufacturing Equipment (HME), suitable for producing complex parts made from a biodegradable thermoplastic polymer, for environmental sustainability. Our new HME equipment is producing PLA parts by both additive and subtractive techniques, with the aim of obtaining accurate PLA components with a good surface quality. A design of experiments has been applied for optimization purposes. The following manufacturing parameters were analyzed: rotation of the spindle, cutting depth, feed rate, layer thickness, nozzle speed, and surface roughness. Linear regression models and neural network models were developed to improve and predict the surface roughness of the manufactured parts. A new test part was designed and manufactured from PLA, to validate the new mathematical models, which can now be applied for producing complex parts made from polymer materials.

1 November 2022 in IOP Conference Series: Materials Science and Engineering
Verified
Conference Paper
Open access
PDF file
PSPascu Sergiu
Pascu Sergiu
NBNicolae Balc
Nicolae Balc
APAdrian Augustin Pop
Adrian Augustin Pop
This paper will discuss the solutions and the main parameters used to print a mold that will be used in a manufacturing process for a personalized implant in orbital fracture situations. The main purpose of this article is to rebuild the damaged orbit. The new orbit should have dimensions and accuracy similar to one of the original elements. Based on the computed tomography (CT) of the patient, the images are extracted and processed. With that information, a customized implant is manufactured. In this article, a case study of a patient suffering from an orbital fracture is presented. Based on the CT images, a mold was printed on additive manufacturing equipment (AM). The manufacturing parameters being highly correlated with the requirements that are needed for this case such as hardness, accuracy, surface roughness and support removal were chosen based on a series of tests and results from other studies. Another aspect that was analysed was related to the material from which was manufactured the mold. The forming and cutting of the mesh are simplified, by introducing the formed metallic mesh making it ready to be applied to real patients and therefore decreasing the effective time required for this kind of operation.