CFRP machining capability by a circular saw

Circular saws have the potential to be part of a high-efficiency machining method for carbon fiber-reinforced plastic (CFRP) compared to endmills and abrasive water jet cutting. This paper highlights the characteristics of machined surfaces and tool failure when CFRP was cut by circular saw. A circular saw is a thin, disk-shaped cutting tool; hence, the saw body often exhibits out-of-plane vibration during the machining process. This vibration affects the quality of the machined surface, as well as tool wear. In order to clarify the effect of vibration on machining characteristics, cutting tests were conducted with/without a pair of damping alloy sheets on either side of the circular saw body. Damping alloy sheets can suppress vibration amplitude. Characteristics of machined surface and tool wear were improved by damping. Surface roughness along the feed direction and laminated direction were 0.5 μm Ra and 1.1 μm Ra, respectively. In addition, we assessed the relationship between carbon fiber orientation and tool wear on CFRP cutting by circular saw. Four fiber orientations (0°, 45°, 90° and −45° against the feed direction) were tested. Cutting force, tool wear, and machined surface were measured after unidirectional CFRP cutting. Results showed that cutting force order was 0°> ± 45° > 90°. Furthermore, finished surface quality was also affected by fiber orientation, with a good surface obtained for 0° fiber orientation, and smaller tool side-flank wear with −45°.