Additively manufactured metals require further surface processing to meet commercial demands and the material characteristics largely differ from conventional metals. Therefore, we perform detailed evaluations on the machinability of these unique metals by assessing cutting forces, machined surface quality, and tool wear. Our approach is to associate cutting chip morphologies and surface generation with the microstructural properties (e.g., grain morphology [1], anisotropic melt pools [2]) of each metal, which enables us to determine optimal process parameters and enhanced machining processes to overcome the inherent microstructural characteristics, such as vibration-assisted machining [3]. We study a wide variety of metals, such as steels [4], aluminum alloys [5], titanium alloys [6], and multi-metals (e.g., CuCrZr [7]).

We also integrate our findings on augmented ultraprecision machining into improving the machinability of additively manufactured metals, such as the application of mechanochemical effects on maraging steel [8] and high-entropy alloy [9].

Publications

[1] Y. Bai, et al., Microstructure and machinability of selective laser melted high-strength maraging steel with heat treatment, Journal of Materials Processing Technology, 288 (2021) 116906.

[2] C. Ni, et al., Effect of material anisotropy on ultra-precision machining of Ti-6Al-4V alloy fabricated by selective laser melting, Journal of Alloys and Compounds, 848 (2020) 156457.

[3] Y. Bai, et al., Optical surface generation on additively manufactured AlSiMg0.75 alloys with ultrasonic vibration-assisted machining, Journal of Materials Processing Technology, 280 (2020) 116597.

[4] Y. Bai, A. Chaudhari, H. Wang, Investigation on the microstructure and machinability of ASTM A131 steel manufactured by directed energy deposition, Journal of Materials Processing Technology, 276 (2020) 116410.

[5] Y. Bai, et al., Unique cellular microstructure-enabled hybrid additive and subtractive manufacturing of aluminium alloy mirror with high strength, Journal of Materials Processing Technology, 320 (2023) 118095.

[6] C. Ni, et al., Effects of machining surface and laser beam scanning strategy on machinability of selective laser melted Ti6Al4V alloy in milling, Materials & Design, 194 (2020) 108880.

[7] Y. Bai, et al., Additively manufactured CuCrZr alloy: Microstructure, mechanical properties and machinability, Materials Science and Engineering: A, 819 (2021) 141528.

[8] Y. Bai, et al., Efficient post-processing of additive manufactured maraging steel enhanced by the mechanochemical effect, International Journal of Machine Tools and Manufacture, 193 (2023) 104086.

[9] L. Xu, et al., Abnormal mechanochemical effect in ultraprecision machining of an additively manufactured precipitation-strengthened high-entropy alloy, Journal of Materials Science and Technology, 170 (2024) 221–237.

Acknowledgements

This research is proudly supported by the A*STAR Industry Alignment Funds (A-0005203-02-00 and A19E1a0097).