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本文鉴定了 6 2Be 38Al锻造合金和 6 5Be 32Al 3Ni铸造合金的机械性能。在室温和高温条件下测定了其抗拉伸强度和延伸率 ,在室温下确定了其断裂韧性。其抗疲劳性依据室温下应力耐久性 (S N)与裂纹扩展应力速率强度范围 (da/dN △K)的关系来定性。并研究了以上所提到性能的试验结果的微观结构和裂纹路径。研究表明 :该锻造合金与铸造合金的显微组织是由铍相颗粒分散在一铝相基体的组织所组成。在锻造合金中铍相颗粒在其压延方向上线性排列 ,而在铸造合金中 ,铍相颗粒粗糙且环绕铝相基体 ,并无方向排列。总之 ,锻造合金比铸造合金有更好的机械性能 ,包括抗疲劳性等。在室温下 ,锻造合金在L T方向和T L方向上的条件平面应变断裂韧性分别为 38.8MPam和 2 2 .4MPam。锻造合金在各种温度下 ,而铸造合金在高温下 ,进行抗拉强度试验 ,抗疲劳性试验和断裂韧性试验时 ,其裂纹路径倾向于沿着铝相和铝 /铍相交界面区域。而在室温下对铸造合金进行抗拉强度试验 ,其裂纹穿过铍相和铝相
This paper identified the mechanical properties of 6 2Be 38Al forged alloys and 6 5Be 32Al 3Ni cast alloys. The tensile strength and elongation at room temperature and high temperature were measured, and its fracture toughness was determined at room temperature. Its fatigue resistance is characterized by the relationship between the stress durability (S N) at room temperature and the strength range of crack propagation stress rate (da / dN ΔK). The microstructure and crack path of the test results of the above-mentioned properties were investigated. The results show that the microstructure of the forged alloy and the cast alloy consists of beryllium phase particles dispersed in an aluminum matrix. In the forged alloy, the beryllium phase particles are linearly arranged in the rolling direction. In the cast alloy, the beryllium phase particles are rough and surround the aluminum phase matrix with no orientation. In summary, forged alloys have better mechanical properties than cast alloys, including fatigue resistance. At room temperature, the for-plane strain-fracture toughness of the forged alloys in the LT and TL directions were 38.8 MPa and 22.4 MPa, respectively. Forged alloys are at various temperatures, and the cracked paths tend to follow the interface of the aluminum and aluminum / beryllium alloys at elevated temperatures for tensile strength, fatigue and fracture toughness tests. At room temperature, however, the tensile strength of the cast alloy was tested and the cracks passed through the beryllium phase and the aluminum phase