Abstract

The influence of the treatment time in a planetary ball mill on the morphology, phase composition, and microstructure of the Al–Mn–Cu-based alloy and the same alloy with nanodiamond particles is studied by X-ray diffraction and scanning electron microscopy. The phase composition of the alloy is determined by X-ray diffraction after casting and milling for 5–20 h. It is shown that nanodiamond particles contribute to the coarsening of granules. The effect was intensified with an increase in the milling time to 20 h. The granular size weakly depends on the processing time for the initial alloy. The Cu-bearing phases of solidification origin are dissolved during milling. The lattice parameter of the aluminum solid solution decreases after five hours of treatment to 0.4028–0.4030 nm, and it increases with further increase in milling time. Exothermic peaks associated with the precipitation of secondary phases are revealed for mechanically alloyed granules during heating. An increase in the milling time reduces the intensity of peaks. The solidus temperature of the alloys decreases after mechanical alloying. For the nanodiamond-bearing sample, a high-temperature exothermic effect, which can be associated to the formation of aluminum carbides or oxidation reactions in nanodiamond particles, is observed. The maximum microhardness is achieved after 5–10 h of milling, and the nanodiamond particles slightly increase the maximum microhardness from 316 to 330 HV. The results indicate the dissolution of copper and manganese in the aluminum solid solution during milling for 5 h and their precipitation with increasing milling time. Nanodiamond particles do not influence the dissolution of elements but accelerate the solid solution decomposition with increasing milling time.

中文翻译：

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高能球磨对Al-Mn-Cu合金组织、相组成和显微硬度的影响

摘要

通过 X 射线衍射和扫描电子显微镜研究了行星式球磨机处理时间对 Al-Mn-Cu 基合金和含有纳米金刚石颗粒的合金的形貌、相组成和微观结构的影响。合金的相组成在铸造和铣削 5-20 小时后通过 X 射线衍射测定。表明纳米金刚石颗粒有助于颗粒的粗化。随着研磨时间增加到 20 小时，效果会更加明显。粒度较弱地取决于初始合金的处理时间。凝固起源的含铜相在铣削过程中溶解。铝固溶体的晶格参数在处理 5 小时后降低至 0.4028-0.4030 nm，并随着研磨时间的进一步增加而增加。对于机械合金化的颗粒，在加热过程中揭示了与第二相沉淀相关的放热峰。研磨时间的增加会降低峰的强度。合金的固相线温度在机械合金化后降低。对于含纳米金刚石的样品，观察到高温放热效应，这可能与碳化铝的形成或纳米金刚石颗粒中的氧化反应有关。研磨 5-10 小时后达到最大显微硬度，纳米金刚石颗粒将最大显微硬度从 316 HV 略微提高到 330 HV。结果表明，在研磨 5 h 的过程中，铜和锰在铝固溶体中的溶解，并且随着研磨时间的增加它们的沉淀。