Copper extrusion 3D printing using metal injection moulding feedstock: Analysis of process parameters for green density and surface roughness optimization

Abstract

In the present study, the extrusion-based 3D printing process was explored using metal injection moulding (MIM) copper feedstock to fabricate dense copper parts. The influence of process parameters of 3D printing, namely layer thickness, nozzle speed, extrusion multiplier and extrusion temperature on green density and surface roughness were studied. Based on the central composite design method, a set of experiments was chosen to study the individual and interaction effects of parameters. Analysis of variance was performed to identify the significant factors and statistical models were obtained by regression analysis. The green density was observed to increase with varying the layer thickness from 0.25 to 0.05 mm and nozzle speed from 100 to 20 mm/s. Similarly, surface roughness was improved by decreasing the layer thickness and the nozzle speed and by increasing the extrusion multiplier up to a specific value. The extrusion temperature gave the best results at 200 ℃ for both green density and surface roughness. The significant interactions between the parameters for both green density and surface roughness were also studied. A multi-objective optimization approach was used to maximize the green density and minimize the surface roughness within the range of the parameters. Micro-tomography scans were used to analyze the porosity and voids in samples printed with optimized and non-optimized parameters. Besides, sintering was performed on the optimized printed sample to fabricate a dense copper part and analyze linear shrinkage during sintering. Sintered copper parts with high density and low surface roughness were obtained with the optimized printing process parameters.

Copper additive manufacturing using MIM feedstock: adjustment of printing, debinding, and sintering parameters for processing dense and defectless parts

“…Finally, the tessellated file was imported in Simplify3D software for orientation and slicing. Optimization of printing parameters was discussed in a previous paper [29]. The design of an experiment-based approach was used to obtain optimal parameters for maximum green density and minimum surface roughness.…”

“…Several printing parameters affect the green density during printing. The effect and optimization of significant parameters such as layer thickness, nozzle speed, extrusion multiplier (flow rate), and extrusion temperature were studied for the green density and surface roughness of the sample in a previous study [29]. The optimized results were obtained to be within 5.42 ± 0.11 g/cm 3 for green density and 3.44 ± 1.59 μm for surface roughness.…”

“…These materials are cheaper because they are produced in large quantities and more effective because they have been designed in terms of binder and metal particle features to provide high-density sintered components. Singh et al [29] presented a 3D printing method for the fabrication of copper parts by extruding a commercial copper MIM feedstock with a screw extruder as used in the MIM process. Design of experiments-based response surface methodology was used to explore the effect of printing parameters (extrusion temperature, nozzle speed, extrusion flow rate multiplier, and layer thickness) on the green density and the surface roughness of the printed sample.…”

Bending Properties of Lightweight Copper Specimens with Different Infill Patterns Produced by Material Extrusion Additive Manufacturing, Solvent Debinding and Sintering

“…As is the case with binder jetting, the shaped part is then subjected to a process of binder removal [43,44] and sintering to densify the parts [15]. Recently, new machines that can work with pellets of metal injection molding (MIM) feedstocks have been developed, and research is being carried out to maximize the performance of the printed specimens with steels [45], hard metals [40], and copper [46]. The advantages of using filament feedstocks are low-cost shaping equipment [47], availability of powders used in traditional powder metallurgical processes, and same feedstock materials are usable in metal injection molding (MIM) or metal extrusion molding (MEM) [48].…”

Effect of different parameters on the tensile properties of printed Polylactic acid samples by FDM: experimental design tested with MDs simulation

“…The extruder is placed on a three-dimensional CNC table that moves in the x, y and z directions and places the molten polymer inside the extruder on the part [31,32]. After nishing one layer, the extruder moves upwards as thick as one layer [33][34][35][36][37]. It is important to note that many parameters affect the quality and nal properties of a sample printed with FDM [38][39][40][41][42].…”