Research on milling performance of CFRP/titanium alloy stacks under low temperature cold wind conditions

Carbon fiber–reinforced polymer (CFRP) and titanium alloy have become the preferred materials for aviation equipment manufacturing due to their excellent mechanical and chemical properties. The high-precision hole-making technology of CFRP/titanium alloy–stacked structure is crucial for ensuring the connection performance of aviation main load-bearing components. However, the significant accumulation of cutting heat during this hole-making process can easily exacerbate tool wear and reduce connecting hole quality. The study developed a low temperature cold wind device based on the Coanda effect and conducted helical/inclined planetary milling hole experiments on CFRP/titanium alloy stacks with/without low temperature cold wind conditions on a rotary worktable for machine tool processing. The effects of cooling device on the machining temperature, milling force, tool wear, and hole quality of helical/inclined planetary milling were analyzed. The research results indicate that the continuous cooling and strong airflow impact of the low temperature cold wind device can significantly reduce the temperature during helical milling and inclined planetary milling, avoiding the serious adhesive wear and cutting edge breakage of the tool, reducing the tearing and burr of the CFRP hole exit and the ablation discoloration of the stacked interface, and lowering the hole wall roughness. As the machining process progresses, the low temperature cold wind device can maintain the cutting temperature at relatively low levels and slow down the wear rate of the milling cutter.