Metal-composite laminates and joints are applied in aircraft manufacturing and maintenance (repairing) using aluminum alloys (AA) and glass fiber-reinforced polymer (GFRP). In these applications, drilling has a prominent place due to its vast application in aeronautical structures’ mechanical joints. Thus, this study presents the influence of uncoated carbide drills (85C, 86C, H10N), cutting speeds ( v c = 20, 40, and 60 m min −1 ), and feed rates ( f = 0.05, 0.15, and 0.25 mm rev −1 ) on delamination factor, thrust force (Ft{F}_{\text{t}}), and burr formation in dry drilling metal-composite laminates and joints (AA2024/GFRP/AA2024). Experiments were performed, analyzed, and optimized using the Box–Behnken statistical design. Microscopic digital images for delamination evaluation, piezoelectric dynamometer for thrust force acquisition, and burr analysis were considered. The major finding was that the thrust force during drilling depends significantly on the feed rate. Another significant factor was the influence of the drill type (combined or not with feed rate). In fact, it was verified that the feed rate and the drill type were the most significant parameters on the delamination factor, while the feed rate was the most relevant on thrust force. The cutting speed did not affect significantly thrust force and delamination factor at exit(FdaS)\hspace{.25em}({F}_{{\text{da}}_{\text{S}}}). However, the combination f × v c was significant in delamination factor at entrance (FdaE)\text{ }({F}_{{\text{da}}_{\text{E}}}). Based on the optimized input parameters, they presented lower values for delamination factors (FdaE=1.18{F}_{{\text{da}}_{\text{E}}}=1.18 and FdaS=1.33{F}_{{\text{da}}_{\text{S}}}=\hspace{.25em}1.33) and thrust force (Ft=67.3N{F}_{\text{t}}=67.3\hspace{.5em}\text{N}). These values were obtained by drilling the metal-composite laminates with 85C-tool, 0.05 mm rev −1 feed rate, and 20 m min −1 cutting speed. However, the burrs at the hole output of AA2024 were considered unsatisfactory for this specific condition, which implies additional investigation.

中文翻译：

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金属复合航空结构的钻孔工艺优化

金属复合材料层压板和接头用于飞机制造和维护（维修），使用铝合金（AA）和玻璃纤维增​​强聚合物（GFRP）。在这些应用中，钻探由于其在航空结构的机械接头中的广泛应用而占有重要的地位。因此，本研究显示了无涂层硬质合金钻头（85C，86C，H10N），切削速度（vc = 20、40和60 m min -1）以及进给速度（f = 0.05、0.15和0.25 mm rev的影响-1）涉及分层因子，推力（Ft {F} _ {\ text {t}}）和干钻金属复合材料层压板和接头中的毛刺形成（AA2024 / GFRP / AA2024）。使用Box–Behnken统计设计进行了实验，分析和优化。显微数字图像，用于分层评估，压电测力计，用于获取推力，考虑毛刺分析。主要发现是，钻孔过程中的推力很大程度上取决于进给速度。另一个重要因素是钻头类型的影响（结合进给率或不结合进给率）。实际上，已证实进给速度和钻头类型是分层因子中最重要的参数，而进给速度与推力最相关。切割速度对出口（FdaS）\ hspace {.25em}（{F} _ {{\ text {da}} _ {\ text {S}}}）的推力和分层系数没有明显影响。但是，组合f×vc在入口处的分层因子（FdaE）\ text {＆＃x00A0;}（{F} _ {{\ text {da}} _ {\ text {E}}}）中很重要。基于优化的输入参数，他们给出了较低的分层因子值（FdaE = 1.18 {F} _ {{\ text {da}} _ {\ text {E}}} = 1.18和FdaS = 1。33 {F} _ {{\ text {t}} _ {\ text {S}}} = \ hspace {.25em} 1.33）和推力（Ft = 67.3N {F} _ {\ text {t}} = 67.3 \ hspace {.5em} \ text {N}）。这些值是通过以85C工具，0.05 mm rev -1的进给速度和20 m min -1的切割速度钻孔金属复合材料层压板而获得的。然而，对于这种特定条件，AA2024的孔输出处的毛刺被认为是不令人满意的，这意味着需要进一步研究。