Metal parts are usually made with costly, energy-hungry machines. This study asks whether a desktop three-dimensional printer, using a metal-filled plastic filament, can make bronze parts strong enough for real engineering work. Metal and ceramic parts are usually made with processes that use a great deal of energy and are expensive to install and maintain.

Material extrusion printing is cheaper, but it is used mostly for plastic parts. The workaround is a plastic filament loaded with metal particles. After printing, the plastic is removed and the metal particles are joined to obtain the final part.

It is a little like shaping a clay object around temporary packing material: the printer first builds the form, then a later heating step leaves the metal structure behind. Bronze parts are used in engineering because they resist corrosion, including in ship propellers, valves, and pumps used around liquids.

Complex bronze shapes can also support custom medical devices. For example, three-dimensional printed bronze shields can reduce radiation doses to healthy tissue beside a surface treatment. Some printed pieces were visibly misshapen: material spilled beyond the intended outline, forming extra ridges and rough edges.

Another had large gaps between neighboring strands, so it was retained only as a reference rather than treated like the reliable prints. The final metal samples were checked for density, shrinkage, and mechanical properties, including stiffness, tensile strength, and how far they stretched before breaking.

The first problem appeared when the printer fed material too slowly: the specimens had excessive voids. Increasing the flow rate produced better filling, with no visible large gaps between neighboring lines or layers. The remaining settings changed the nozzle temperature, the pattern of intermediate layers, and whether the printer pressed the surface smooth with an ironing pass.

The results show that tensile strength increases when the intermediate layers use a linear pattern and ironing is not activated. Looking at both the density of the sintered parts and their shrinkage, sets B and C could represent the best trade-off. The results were generally not widely spread, especially for density.

Sets C and E behaved similarly and produced the best results for strength and strain, while sets B and D had the lowest stiffness, tensile strength, and stretch before breaking. The clearest difference in stretch before breaking emerged between sets B and C, supporting the idea that the settings can change how the finished bronze behaves.

Material extrusion printing is becoming more interesting for metal parts because it offers a low-cost alternative while allowing different metals to be used. MEAM is attracting growing interest as a valid, low-cost alternative for metal production, while retaining the advantages of other additive manufacturing technologies and allowing flexibility across different metals.

In this study, the researchers tested three printing parameters, nozzle temperature, intermediate-layer pattern, and ironing, against a reference set using the filament manufacturer’s recommended settings. The printer can make useful bronze, but the settings matter: how material is fed, how layers are arranged, and whether the surface is pressed smooth can change both internal flaws and final strength.

That could make custom metal parts more accessible.