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Effect of Processing on 3D Printed Materials (Advert Reference: FAC19/EE/MCE/LAFDI2)

Project Description

Additive manufacturing (AM), also called 3D printing, represents an emerging technique for building complex geometries and for rapid prototyping. In the last 5 years, AM has rapidly evolved from the laboratory scale to the manufacturing of commercial parts. Depending on the material and machine technology, there are several different processes to perform layer manufacturing. Among them, fused filament fabrication (FFF). Although FFF of various polymers has already been commercialized, there is still the need to perform some fundamental studies to improve the process. For example, the development of porosity between the deposited filaments or the crystallization induced during the 3D printing process are critical issues that can compromise the quality of the final product, and hence it is extremely important to understand how to control these phenomena.

The printing conditions, such as the nozzle temperature, build-platform temperature, printing speed/pressure, nozzle movement speed and extrusion speed, influence the printed parts properties. In particular, the printing temperature greatly influences the relaxation phenomena of polymer chains. Besides the instrumentation, the quality of the raw material also plays an important role. Considering the numerous printing parameters, optimal printing conditions are challenging and may require several iterations of trial and error corrections before printing appropriately, especially when the polymer is semi-crystalline. This study aims to investigate physical changes during the 3D printing of polymers such as polylactic acid (PLA). The correlations between the chemistry, surface topography, orientation, porosity, crystallinity and mechanical properties of the printed parts will be studied. Moreover, the effects of the build-platform temperature will be investigated. The experimental results confirmed the anisotropy of printed objects due to the occurrence of orientation phenomena during the filament deposition and the formation both of ordered and disordered crystalline forms. A post-treatment will be proposed as a solution to improve the printed products’ mechanical properties.

The Principal Supervisor for this project is Professor Khalid Lafdi.

Please note eligibility requirement:
• Academic excellence of the proposed student i.e. 2:1 (or equivalent GPA from non-UK universities [preference for 1st class honours]); or a Masters (preference for Merit or above); or APEL evidence of substantial practitioner achievement.
• Appropriate IELTS score, if required.
• Applicants cannot apply for this funding if currently engaged in Doctoral study at Northumbria or elsewhere.

For more information and informal enquiries please contact Prof. Khalid Lafdi. E-mail:

For further details of how to apply, entry requirements and the application form, see

Please note: Applications that do not include a research proposal of approximately 1,000 words (not a copy of the advert), or that do not include the advert reference (e.g. FAC19/EE/MCE/LAFDI2) will not be considered.

Start Date: 1 March 2020

Northumbria University takes pride in, and values, the quality and diversity of our staff. We welcome applications from all members of the community. The University holds an Athena SWAN Bronze award in recognition of our commitment to improving employment practices for the advancement of gender equality and is a member of the Euraxess network, which delivers information and support to professional researchers.

Funding Notes

The studentship is available to Students Worldwide, and covers full fees and a full stipend, paid for three years at RCUK rates (for 2019/0, this is £15,009 pa).


• Raimondo, M., Guadagno, L., Vertuccio, L., Naddeo, C., Barra, G., Spinelli, G., & Lafdi, K. (2018). Electrical conductivity of carbon nanofiber reinforced resins: potentiality of tunneling atomic force microscopy (TUNA) technique. Composites Part B: Engineering, 143, 148-160.
• El Moumen, A., Tarfaoui, M., & Lafdi, K. (2018). Computational homogenization of mechanical properties for laminate composites reinforced with thin film made of carbon nanotubes. Applied Composite Materials, 25(3), 569-588.
• El Moumen, A., Tarfaoui, M., & Lafdi, K. (2019). Additive manufacturing of polymer composites: Processing and modeling approaches . Composites Part B: Engineering, vol 171 Pages 166-182

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