Post-treatments for Additive Manufactured Parts
Parts manufactured in Additive Manufacturing equipment can not be used immediately, and additional treatments must be carried out to improve their mechanical properties. . These can be thermal, mechanical or even chemical treatments. Here are a few examples of post-treatments for Additive Manufactured parts
High speed milling
Parts produced through additive manufacturing almost invariably need machining as a follow-up step.
CNC machining is typically used to mill a parts out of a block of material, but it has also been adopted as
a secondary process for additive manufacturing technology. Machining can function as a secondary operation
to achieve very specific dimensional tolerances. It’s also often used to add threads for inserts.
Hot isostatic pressing (HIP)
HIP involves the simultaneous application of high temperature and pressure to a parts.
At higher diffusion rates associated with temperatures, the applied pressure leads
to increase the density of the parts. HIP is used to eliminate pore and remove defects, i.e. nitrides,
oxides and carbides, to dramatically increase the material properties.
This process helps improve the condition of a part and reduce surface roughness.
To reach this objective, a laser will locally improve surface topography and
locally melt the steep slopes and allow molten material to ﬂow into the valleys.
Stress relief furnace
Parts processed by laser-based additive manufacturing are usually followed with a stress relief treatment
as rapid cooling laser process induce residual stresses in the part. The heat treatment eliminates internal stresses caused by
additive manufacturing. By means of a heat treatment a specific adjustment of the mechanical characteristics is possible.
Laser peening is a surface engineering processes used to impart beneficial residual stresses in material.
It significantly improves mechanical behaviors such as fatigue resistance and fatigue strength.
Electro-polishing is an electrochemical process that removes undesirable material from the surface of a metal parts. It is use to polish, passivation, and deburr metal parts.
According to the additive manufacturing processes used, the nature of the material and application requested, some post-treatments will be chosen to ensure quality parts in compliance with functional and metrological speciﬁcations. Z3DFAB will introduce 10 equipment for machining and heat-treatment by the end of 2018.
and can outsource some of the operations, when needed.