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本文用屈服强度对温度和应变速率的依赖关系来分析纯铝因形成空位而产生的强化特性。纯度为99.99％的铝棒经淬火和热处理后形成空位、其密度约为10~13～10~14空位/厘米~3。可用电子显镜观测所选试样内的空位。在77～593K温度范围和3.33×10~-2/秒、1.67×10~-3/秒两种应变速率下,测定了空位强化试样的屈服强度。在室温和77K二种温度下,以不同的应变速率也进行了试验。业已发现,Coulomb的空位强化的研究和包括Ashby对称振子准则在内的Oro-Wan应力的研究,二者有相似性,已确定空位强化的程度和有效性主要取决于空位密度,而与空位尺寸关系不大。发现室温下测得的强化值和予算值相一致。与退火铝相比,空位强化铝对低温下塑性流变不稳定性更为敏感;屈服强度对温度的依赖关系随不同温度区间而变化,其屈服强度有较高的应交速率灵敏度。
In this paper, the dependence of yield strength on temperature and strain rate is used to analyze the strengthening properties of pure aluminum due to the formation of vacancies. The purity of 99.99% aluminum rods after quenching and heat treatment to form vacancies, the density of about 10 ~ 13 ~ 10 ~ 14 vacancies / cm ~ 3. Electron microscope observation of vacancies in the selected sample. The yield strengths of the vacancy-hardening specimens were measured at 77-559 K and at strain rates of 3.33 × 10 -2 / s and 1.67 × 10 -3 / s. At room temperature and 77K two kinds of temperatures, also tested at different strain rates. It has been found that both the Coulomb space-enhanced study and the Oro-Wan stress study including the Ashby Symmetry Oscillator Criterion have similarities and the degree and effectiveness of the determined space-enhancement are mainly determined by the vacancy density but not by the vacancy size Little relationship. It was found that the intensities measured at room temperature are consistent with the calculated values. Compared with annealed aluminum, vacancy reinforced aluminum is more sensitive to plastic rheological instability at low temperature. The dependence of yield strength on temperature varies with different temperature ranges, and the yield strength has a higher rate sensitivity.