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Materials Science in Additive Manufacturing Quality of a 3D-printed steel part

Build Processor, ensures a high level of process reliability, Various commercial and standardized designations exist
with tools for development, simulation, 3D printing, and for maraging steel powder feedstock similar to that used
numerical control programming for metal parts that are in this study. Examples include M300 Tool Steel (LPW),
not integrated into a single system. Converting geometry Maraging Steel (3D Systems), 1.2709 (EN 10027-2; SLM
to STL is required first, and the software package includes Solutions; SANDVIK), MS1 (EOS), CL 50WS (Concept
a TRUMPF Build Processor that handles slicing and Laser), X3NiCoMoTi 18-9-5 (DIN EN 10027-1), Tool
hatching build jobs, as well as parameter management Steel 1.2709-A LMF (TRUMPF) and 18Ni-300 (MIL-S-
(Figure 2). This well-defined digital printing workflow is 46850D). This kind of steel is characterized by having very
efficient, allowing for time and cost savings. good mechanical properties and being easily heat-treatable
using a simple thermal age-hardening process. Maraging
2.2. Maraging steel properties and metallurgy steels are a subclass of high-strength steels that differ from
Steel is a widely utilized engineering material, with conventional steels in that they are hardened through a non-
numerous alloys that are well-suited for AM due to carbon metallurgical reaction. Rather than that, these steels
their excellent weldability and castability. Steel alloys are are strengthened through the precipitation of intermetallic
generally classified into four main groups: carbon steels, compounds at temperatures of approximately 500°C. The
alloy steels, stainless steels, and tool steels. Maraging term “maraging” is derived from martensite age hardening
steels, a subset of high-alloy steels, primarily contain and refers to the age-hardening of a martensite matrix
15 – 25% nickel and have a low carbon content. Their composed of low carbon, iron-nickel laths. Commercial
strength is derived from the formation of a soft martensitic maraging steels are designed to have a yield strength
structure, which undergoes significant hardening through ranging from 1000 to 2400 MPa and certain experimental
the precipitation of intermetallic compounds during the maraging steels exhibit yield strengths up to nearly 3500
aging process. Maraging steels offer several advantages MPa. 43,44 These steels typically contain extremely high
that make them particularly appealing for AM. Their amounts of nickel, cobalt, and molybdenum and very little
exceptional strength-to-weight ratio, outstanding ductility, carbon. Indeed, carbon is an impurity in these steels and
and excellent fatigue resistance enable the production of is kept to a minimum commercially feasible level to avoid
lightweight, high-performance components. In addition, the formation of titanium carbide (TiC), which can have
their low thermal expansion coefficient and superior a detrimental effect on strength, ductility, and toughness.
thermal stability minimize distortion during the AM Various maraging steel varieties have been developed for
process, leading to more precise dimensional accuracy. specialized applications. Maraging steels are manufactured
Although maraging steels are not classified as traditional commercially in the United States and abroad by a variety
tool steels, their exceptional malleability, and thermal of steel companies. Due to the absence of carbon and the
stability make them suitable for similar applications. As a use of intermetallic precipitation to achieve hardening,
result, they are sometimes informally referred to as “tool maraging steels exhibit several unique properties that
steels.” distinguish them from conventional steels. Hardenability

Figure 2. 3D printing digital processing workflow and data preparation for laser metal fusion
Source: TRUMPF

Volume 4 Issue 2 (2025) 5 doi: 10.36922/MSAM025040002