The present work investigates the microstructure development and mechanical properties of mechanically alloyed and hot-pressed copper (Cu)-X wt pct aluminum (Al) (X = 0, 3, 5, 10, 15) alloys. The morphology of the ball-milled Cu-Al powders changed from coarse flaky structure to small hard agglomerates with the addition of Al. It was observed that the density of Cu-Al samples varied between ~ 95 and 98 pct of theoretical density (ρ_th) after hot pressing (Temperature: 500 °C, Pressure: 500 MPa, Time: 30 min). The crystallite size of Cu-Al samples decreased for both the milled powders and hot-pressed samples. The XRD and SEM-EDS analyses of the hot-pressed samples confirmed the presence of α-Cu solid solution phases for the Cu alloyed with Al up to 5 wt pct. On the other hand, further addition of Al to Cu leads to the formation of both intermetallic compound (Cu₉Al₄) and solid solution phase. The nano-indentation tests indicated a significant increase in hardness (2.4 to 7.9 GPa) and elastic modulus (121.1 to 177.4 GPa) of Cu-Al alloys. The Cu-Al alloys were measured with very high compressive strength (813.8 to 1120.2 MPa) and the compressive strain varied in the range of 29.81 to 5.81 pct.

中文翻译：

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极其坚硬和坚固的Cu-（0-15 wt pct）Al合金的加工与表征

本工作研究了机械合金化和热压铜（Cu）-X  wt pct铝（Al）（X  = 0、3、5、10、15 ）合金的微观结构发展和力学性能。加入Al后，球磨Cu-Al粉末的形态从粗鳞片状变为小硬块状。据观察，〜95和98厘理论密度的之间变化铜铝样品的密度（ρ_个）热压后（温度：500°C，压力：500 MPa，时间：30分钟）。对于研磨粉和热压样品，Cu-Al样品的微晶尺寸均减小。对热压样品的XRD和SEM-EDS分析证实，与Al含量不超过5 wt％的Al合金化的Cu存在α-Cu固溶体相。另一方面，将Al进一步添加至Cu导致金属间化合物（Cu ₉ Al ₄）和固溶相的形成。纳米压痕测试表明，Cu-Al合金的硬度（2.4至7.9 GPa）和弹性模量（121.1至177.4 GPa）显着增加。以非常高的抗压强度（813.8至1120.2 MPa）对Cu-Al合金进行了测量，其压缩应变在29.81至5.81 pct的范围内变化。