By superposition, the individual strengthening mechanisms via hardness analyses and the particle dispersion contribution to strengthening were estimated for Al–C and Al–C–Cu composites and pure Al. An evident contribution to hardening due to the density of dislocations was observed for all samples; the presence of relatively high-density values was the result of the difference in the coefficients of thermal expansion (CTE) between the matrix and the reinforced particles when the composites were subjected to the sintering process. However, for the Al–C–Cu composites, the dispersion of the particles had an important effect on the strengthening. For the Al–C–Cu composites, the maximum increase in microhardness was ~210% compared to the pure Al sample processed under the same conditions. The crystallite size and dislocation density contribution to strengthening were calculated using the Langford–Cohen and Taylor equations from the microstructural analysis, respectively. The estimated microhardness values had a good correlation with the experimental. According to the results, the Cu content is responsible for integrating and dispersing the Al₄C₃ phase. The proposed mathematical equation includes the combined effect of the content of C and Cu (in weight percent). The composites were fabricated following a powder metallurgical route complemented with the mechanical alloying (MA) process. Microstructural analyses were carried out through X-ray analyses coupled with a convolutional multiple whole profile (CMWP) fitting program to determine the crystallite size and dislocation density.

中文翻译：

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Al4C3纳米复合材料对Al-Cu增强体组织和硬度的影响

通过叠加，对 Al-C 和 Al-C-Cu 复合材料和纯铝，通过硬度分析和颗粒分散对强化的贡献估计了单独的强化机制。所有样品都观察到位错密度对硬化的明显贡献；相对高密度值的存在是复合材料经受烧结过程时基体和增强颗粒之间的热膨胀系数 (CTE) 差异的结果。然而，对于Al-C-Cu复合材料，颗粒的分散对强化有重要影响。对于 Al-C-Cu 复合材料，与在相同条件下处理的纯 Al 样品相比，显微硬度的最大增加约为 210%。分别使用来自显微结构分析的 Langford-Cohen 和 Taylor 方程计算微晶尺寸和位错密度对强化的贡献。估计的显微硬度值与实验具有良好的相关性。根据结果​​，Cu 含量负责整合和分散 Al₄ C ₃相。提出的数学方程包括 C 和 Cu 含量（重量百分比）的综合影响。复合材料是按照粉末冶金路线制造的，辅以机械合金化 (MA) 工艺。微观结构分析是通过 X 射线分析结合卷积多重整体轮廓 (CMWP) 拟合程序进行的，以确定微晶尺寸和位错密度。