The process diagram presents water and terracotta clay powder combined before screw-based material extrusion, M E X, for clay 3 D printing. The printed mould is then filled with iron powder, and a copper ingot is placed on top. The filled mould moves to a sintering furnace, then to an iron-copper alloy cylinder. The final stage is testing and characterisation, with compression testing, pin-on-disc testing, and two microscopic views.The process diagram presents water and terracotta clay powder combined before screw-based material extrusion, M E X, for clay 3 D printing. The printed mould is then filled with iron powder, and a copper ingot is placed on top. The filled mould moves to a sintering furnace, then to an iron-copper alloy cylinder. The final stage is testing and characterisation, with compression testing, pin-on-disc testing, and two microscopic views.This study aims to explore a cost-effective and eco-friendly approach for producing custom metal/alloy parts using pressureless sintering into clay three-dimensional (3D)-printed molds. Specifically, it investigates the feasibility of manufacturing iron–copper (Fe–Cu) alloy parts using this novel technique.
This study uses material extrusion-based additive manufacturing of terracotta clay molds for the synthesis of Fe–Cu alloys. The fabrication process uses pressureless, in situ Cu infiltration, driven by capillary action into a consolidated Fe powder matrix. Using a full factorial design of experiments framework, this study evaluates the synergetic effects of sintering temperature, heating rate and sintering time (holding duration) on the evolution of the microstructure and the overall quality of the final parts. The mechanical and tribological performance of the fabricated Fe–Cu composites was quantified through microhardness, compressive strength and wear rate assessments. These evaluations were complemented by microstructural characterization to elucidate the fundamental relationships between processing parameters and resultant material properties.
The fabricated Fe–Cu alloy parts were evaluated based on microhardness, compressive strength and wear rate. Microstructural characterization was conducted to assess the influence of the processing parameters on the final properties. Evaluation of the mechanical properties revealed that the pressureless sintering into clay molds (PSIC)-fabricated parts attained a maximum microhardness of 163.45 HV and a notable compressive strength of 695 MPa. Furthermore, the specimens exhibited enhanced tribological performance, with wear rates as low as 0.07 µm/s.
This work presents a novel integration of clay 3D printing with in situ metal infiltration for alloy part production, offering a sustainable and cost-efficient alternative to conventional metal manufacturing methods. The approach opens possibilities for low-cost, customized metal/alloy fabrication using accessible materials and additive manufacturing.
