Marco Zago

The project aims at developing design approaches for compensating sintering distortion of Metal Binder Jetting products. The candidate will model the sintering distortion of a case-study geometry by finite element methods (first method: thermo-elastic material behavior; second method: thermo-viscous-plastic material behavior). A compensated geometry will be designed, fabricated, and measured by means of a coordinate measuring machine (CMM) in order to assess the effectiveness of the compensation approaches.   

The project aims at investigating the dimensional and geometrical precision of a benchmark fabricated by Metal Binder Jetting process. The work aims at assessing the process capability of MBJ on the fabrication of small, medium, and large size products. In addition, the project wants to highlight the influence of process conditions (location in the building box, influence of density …) on the precision of product in order to develop a robust design approach. The candidate will measure the dimensional and geometrical precision of benchmark samples at green and sintered state. Deviation from nominal geometry will be analyzed and counteract design strategies will be defined: new scaling factor, geometry re-design, optimum arrangement of product in the building box.

JETCELL project is aimed to redesign the anode of a Molten Hydroxide Direct Carbon Fuel Cell (MH-DCFC) through the exploitation of additive manufacturing (AM) flexibility and near free-of-constrain production by means of binder jetting (BJ) technology. In a MH-DCFC cell, the anode represents the electrode where the carbonaceous fuel is oxidized liberating electrons and producing electricity. In the current configuration, the fuel cell is fed per batch, thus limiting the possibility of continuous working requiring the interruption of electrical connection to remove exhaust fuel. Thus, the design of an innovative anode capable to be fed continuously meanwhile evacuating the burn fuel is a challenge that must be faced, aiming at reaching the goal of carbon neutrality by scheduled time.

Since the efficiency of DCFC can be augmented by the use of oxidic catalysts made by iron oxide, lime and magnesia, red muds (RM) will be also employed in cell design. By this choice, a specific use of this absolutely hazardous and environmental concerning waste can be defined, solving one of the biggest issues affecting the primary alumina industry. Metallic (AISI 316L stainless steel) and composite (AISI 316L+RM) anodes will be printed with several geometries (tea-bag and double helix DNA-like shape) and tested in a laboratory scale MH-DCFC cell with traditional configuration, currently using biochar as fuel. Furthermore, insulating-catalytic coating made by red mud will be deposited on the inner crucible walls to maximize the share of use of red mud within this technology. Expected results of the investigation are the possibility of producing anodes really capable to be fed and discharge continuously while exploiting the catalytic properties of the iron oxides contained in the red muds.

Additive manufacturing (AM) technology holds the potential to produce a green revolution in manufacturing production, driven by enhanced product efficiency, more sustainable material utilization, and energy conservation. Among various AM techniques, binder jetting (BJ) technology is gathering significant attention due to its scalability and competitive cost of production. BJ involves three essential stages: printing, de-binding, and sintering. During printing, layers of powder are joined using a polymeric agent which constitutes up to 5%wt of the printed part. Subsequently, de-binding eliminates the binder, releasing CO2 into the atmosphere, while sintering densifies particles into a solid structure.

The use of polymeric binder during printing poses a challenge in reducing CO2 emissions. This project aims to exploit a novel design approach by integrating shell-based structures with cellular infill strategies. The focus is on re-designing the 3D product geometry, where the external surface remains unchanged while internal volume is replaced by an infill pattern. This innovative methodology preserves the nominal geometry, as the hollow space is filled with unbonded particles during printing. The primary objective of this design is a significant reduction in binder usage.

The proposed thesis aims to investigate and characterize the distribution of porosity in Binder Jetting samples using micro CT (Computed Tomography) scanning. The research will employ a Design of Experiments (DoE) approach to systematically vary printing conditions and study their influence on porosity characteristics. The study will also involve learning image processing techniques to analyze and interpret the CT data. Additionally, the student will have the opportunity to gain valuable international experience by spending a period abroad at Eindhoven University in the Netherlands starting from September/October.

Interest students are warmly invited to contact me.