Analysis of Density, Roughness, and Accuracy of the Atomic Diffusion Additive Manufacturing (ADAM) Process for Metal Parts.

Manuela Galati,Paolo Minetola

doi:10.3390/ma12244122

Abstract

Atomic Diffusion Additive Manufacturing (ADAM) is a recent layer-wise process patented by Markforged for metals based on material extrusion. ADAM can be classified as an indirect additive manufacturing process in which a filament of metal powder encased in a plastic binder is used. After the fabrication of a green part, the plastic binder is removed by the post-treatments of washing and sintering (frittage). The aim of this work is to provide a preliminary characterisation of the ADAM process using Markforged Metal X, the unique system currently available on the market. Particularly, the density of printed 17-4 PH material is investigated, varying the layer thickness and the sample size. The dimensional accuracy of the ADAM process is evaluated using the ISO IT grades of a reference artefact. Due to the deposition strategy, the final density of the material results in being strongly dependent on the layer thickness and the size of the sample. The density of the material is low if compared to the material processed by powder bed AM processes. The superficial roughness is strongly dependent upon the layer thickness, but higher than that of other metal additive manufacturing processes because of the use of raw material in the filament form. The accuracy of the process achieves the IT13 grade that is comparable to that of traditional processes for the production of semi-finished metal parts.

Highlights

Additive manufacturing (AM) processes are revolutionizing the way engineers and designers can conceive and fabricate a product, thanks to the higher design freedom
The comparison between the dimensions of the cubes before and after the sintering phase shows that the samples which were built with a lower layer thickness have a higher shrinkage factor if compared to the samples which were built with a layer thickness of 0.125 mm
In this paper the results of analyses focusing on the density, surface roughness and dimensional accuracy of 17-4 PH samples manufactured by means of Atomic Diffusion Additive Manufacturing patented by Markforged Inc. are presented

Summary

Introduction

Additive manufacturing (AM) processes are revolutionizing the way engineers and designers can conceive and fabricate a product, thanks to the higher design freedom. The AM processes developed for metal components are mainly powder bed-based, in which an energy source is used to selectively melt the material. Due to the inefficiency and low power of the energy sources, the earliest metal AM machines were only indirect manufacturing systems because post-treatments were necessary to obtain a part with relatively good mechanical performance. In those earliest processes, the metallic powder was mixed with a polymeric binder

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