Unveiling damage mechanisms of SiC fiber-reinforced titanium matrix composites through ultrasonic scratching

• Published in: Journal of cleaner production Vol. 466; p. 142820
• Main Authors: Wang, Liyu, Yuan, Songmei, Gao, Xiaoxing, Li, Qilin, Xu, Weiwei, An, Wenzhao, Luo, Yang, Chen, Bochuan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10-08-2024
• Subjects: Clean processing; Damage mechanisms; Fibre deformation; Metal-matrix composites (MMCs); Ultrasonic vibration-assisted machining; Metal-matrix composites (MMCs); Ultrasonic vibration-assisted machining; Clean processing; Fibre deformation; Damage mechanisms
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2024.142820

SiCf/Ti composites are increasingly being utilized in the aerospace field due to their excellent performance. However, during the application of this material, issues such as fiber fracture and debonding often occur during processing. Ultrasonic vibration-assisted machining technology avoids the waste of cutting fluid and its environmental impact in traditional production, making it widely used in the ultra-precision and environmentally friendly processing of composite materials. This study explores the damage formation mechanism during material removal using diamond scratching. A comparison was made between the specific energy and morphology of ultrasonic scratching and conventional scratching, and a model for fiber fracture depth was established. The results indicate that conventional cutting leads to fiber bending and crushing, with bent fibers causing deformation to the matrix, which further affects the fibers behind. EBSD results confirm that fiber bending deformation affects the microstructure changes in the matrix. Under ultrasonic scratching, scratching force and specific energy decreased by 25% and 50%, respectively, compared to conventional scratching. This effectively reduces the deformation of fibers on the matrix during cutting and enhances the tool's ability to shear and remove fibers. CT analysis of the subsurface showed that under ultrasonic scratching, the maximum decrease in fiber fracture depth was 13% compared to traditional methods. This study guides the clean and low-damage machining of SiCf/Ti composites.
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•The damage formation mechanism of SiCf/Ti exhibits a “domino effect”.•During the processing of SiCf/Ti, the fibers may undergo multiple fractures.•Ultrasonic scratching reduces scratching force, specific energy, and fracture depth.•A Prediction model of multiple fiber fractures of processed SiCf/Ti was established.•The UVAM can effectively reduce the processing damage of SiCf/Ti.