{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T10:10:06Z","timestamp":1789035006425,"version":"build-2803163510"},"reference-count":39,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T00:00:00Z","timestamp":1788998400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Ultrasonic vibration-assisted machining (UVAM) can improve the machinability of difficult-to-machine titanium alloys; however, the relationship between machining-load fluctuations, subsurface microstructure, and electrochemical response remains insufficiently established. In this study, a wireless in-situ monitoring system was integrated with electron backscatter diffraction (EBSD), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and scanning electrochemical microscopy (SECM) to compare conventional milling (CM), low-excitation UVAM (L-UVAM), and high-excitation UVAM (H-UVAM) of Ti-6Al-4V. Under the investigated conditions, H-UVAM reduced the RMS value of the measured axial load signal by 43.3% compared with CM and decreased the variation in the resultant bending-moment signal. The EBSD results showed a reduction in the mean grain size from 11.67 \u03bcm for CM to 10.07 \u03bcm for H-UVAM, together with an increase in the measured high-angle grain-boundary fraction from 48.27% to 59.39%. Electrochemical measurements further indicated a lower corrosion current density and a higher fitted barrier resistance for the H-UVAM surface. SECM mapping showed a narrower local current distribution under H-UVAM than under CM. These results demonstrate a consistent association between reduced machining-load fluctuations, modified subsurface crystallographic features, and improved electrochemical response. Because surface roughness, residual stress, tool wear, and passive-film chemistry were not independently quantified, the present work does not attribute the corrosion response exclusively to microstructural changes. Instead, it provides a cross-scale experimental framework for correlating machining dynamics with surface integrity and corrosion-related performance in machined titanium alloys.<\/jats:p>","DOI":"10.3390\/ma19183850","type":"journal-article","created":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T09:13:03Z","timestamp":1789031583000},"page":"3850","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["In-Situ Monitoring of Machining Loads and Cross-Scale Characterization of Surface Integrity and Electrochemical Response During Ultrasonic-Assisted Milling of Ti-6Al-4V"],"prefix":"10.3390","volume":"19","author":[{"given":"Qian","family":"Qiao","sequence":"first","affiliation":[{"name":"IDQ Science and Technology (Hengqin, Guangdong) Co., Ltd., Zhuhai 519000, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-4528-5239","authenticated-orcid":false,"given":"Dawei","family":"Guo","sequence":"additional","affiliation":[{"name":"IDQ Science and Technology (Hengqin, Guangdong) Co., Ltd., Zhuhai 519000, China"},{"name":"Institute for the Development and Quality, University of Macau, Macao 999078, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6414-1393","authenticated-orcid":false,"given":"Chi-Tat","family":"Kwok","sequence":"additional","affiliation":[{"name":"Department of Electromechanical Engineering, University of Macau, Macao 999078, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"data-curation","vocabulary":"credit"}]},{"given":"Lap-Mou","family":"Tam","sequence":"additional","affiliation":[{"name":"IDQ Science and Technology (Hengqin, Guangdong) Co., Ltd., Zhuhai 519000, China"},{"name":"Department of Electromechanical Engineering, University of Macau, Macao 999078, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"funding-acquisition","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"150373","DOI":"10.1016\/j.msea.2026.150373","article-title":"Low-cost and additive manufacturable TC4-based alloys with improved strength-ductility synergy","volume":"966","author":"He","year":"2026","journal-title":"Mater. 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