Belgian scientsits have taken on a unique study in evaluating AM parts, releasing their findings in ‘Influence of Conventional Machining on Chemical Finishing of Ti6A14V Electron Beam Melting Parts.’ Acknowledging the positive impacts additive manufacturing has made in a wide range of industries—from medicine to aerospace, construction, and so much more—the authors point out that there is still much to learn as challenges continue to arise in the face of ongoing innovation.
In this study, titanium alloy printing (Ti6Al4V) with electron beam melting (EBM) is the focus, along with challenges in production—mainly dealing with roughness that reduces necessary resistance to fatigue. Such defects can be common and may discourage users from branching out into using new technology.
Finishing is often required to ensure optimum performance, with numerous processes available for refining the surface further:
- Shot peening
- Vibratory finishing
- Conventional machining
- Laser polishing
- Shape adaptive grinding
- Electrochemical treatments such as chemical etching, electrochemical polishing, and plasma electrolytic polishing
Samples were printed and then evaluated, as the researchers compared the roughness of Ti6Al4V EBM parts that were chemically finished before and after robotic machining. An Arcam A2 machine was used for printing, and part and core surfaces were evaluated, using cylindricity and roughness measurements.In experimenting and comparing the effects of conventional machining on chemical finishing, the researchers employed four steps:
- Preliminary analysis
- First chemical etching
- Robotic milling
- Second chemical etching
Arithmetic roughness was minimally affected by the first chemical etching, showing a decrease of 2.5 percent.
“Roughness decreases dramatically after robotic milling and reaches results < 0.5 μm for some parts (reduction of 97%),” stated the authors. “This last roughness result allows to foresee demanding application of the treated part cylinder according recommendation of Ra < 1.6 μm for contact surface.”
Ultimately, total roughness measurement conclusions were the same as RA in the initial chemical etching, showing a decrease of 6.5 percent, and 95 percent for robotic milling:
“These measurements have been only made on two parts. So, it would be interesting to pursue analysis and make a chemical etching with more parts robotically milled beforehand to assess this influence of chemical etching on robotic milling in terms of Rt,” stated the researchers.
“Even if the parts were coming from the same region of the building plate, cylindricity of raw parts were heterogeneous (σ = 0.027 mm for an average cylindricity of 0.062 mm). The first chemical etching did not change these results. However, robotic milling degraded cylindricity of the part by 300% due to the process itself. Chemical etching does not degrade cylindricity while robotic milling does,” concluded the researchers.
“This process is very promising since it allows to treat the part regardless of its geometry and without inducing stresses on the part surface. However, it was not possible to reach an arithmetic roughness as good as after robotic milling. Moreover, after having applied a chemical etching on the core material of the part, Rt increased and the shiny surface became dull. More analysis will be required to assess if this aspect modification is linked to a metallurgical change of the part surface material.”
Titanium has been the source of much research to date, from evaluation of scaffolds in bioprinting to testing medical devices, improving 3D-printed implants, and more. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.[Source / Image: ‘Influence of Conventional Machining on Chemical Finishing of Ti6A14V Electron Beam Melting Parts’]
You May Also Like
MX3D Receives €2.25M to Commercialize Metal 3D Printing Welding Robots
Perhaps most known for 3D printing a massive steel bridge in the Netherlands, Dutch startup MX3D has recently received a €2.25 million investment. Funding came from DOEN Participaties, PDENH, and...
AIM Sweden and HP 3D Print Molded Fiber Tooling for Packaging
2021 is really shaping up to be the year of the application, capitalization, and consolidation. Many companies are being bought to facilitate market entry by new players. We are also...
Wi3DP to Host 3rd Edition of “Meet the Stars of 3D Printing” with Automotive Expert Panel
The upcoming edition of “Meet the Stars of 3D Printing” will explore how students and young professionals interested in additive manufacturing (AM) can build a successful career in the automotive...
Sustainable, Customizable 3D Printed Flip Flops Available on Kickstarter
It’s April in Ohio, which means that it’s almost time for me to bust out my various flip flops and welcome the warm summer weather! We often hear about 3D...
View our broad assortment of in house and third party products.