1. The influence of the solution treatment process of industrial aluminum profiles
In order to obtain a good aging strengthening effect, the quenching heating temperature should be higher and the holding time should be longer under the condition of no overheating, overburning and grain growth, which is conducive to obtaining a uniform solid solution with maximum supersaturation; In addition, the second phase cannot be precipitated during the quenching and cooling process, otherwise it will cause local uneven precipitation and reduce the aging strengthening effect.
2. The regression phenomenon of industrial aluminum profiles
In theory, the regression treatment is not limited by the number of treatments, but in fact, it is difficult to completely re-dissolve the precipitated phase during the regression treatment, resulting in partial precipitation of the precipitated phase in the subsequent aging process, which gradually weakens the aging strengthening effect. Therefore, the regression treatment is only used for repairing rivet alloys used in aircrafts, and this phenomenon can be used for riveting at any time, but it has little use value for other industrial aluminum profiles.
3. The influence of aging temperature
When aging at different temperatures, the critical crystal nucleus size, quantity, composition, and aggregation growth speed of the precipitated phase are different. If the temperature is too low, the GP zone is not easy to form due to difficult diffusion, and the strength and hardness after aging are low, and the aging temperature is too high. When it is high, diffusion is easy to proceed, the critical crystal nucleus size of the precipitated phase in the supersaturated solid solution is large, and the strength and hardness after aging are low, that is, overaging occurs.
4. The influence of the chemical composition of industrial aluminum profiles
Whether an alloy can be strengthened by aging depends firstly on whether the elements that make up the alloy can be dissolved in solid solution and the degree to which the solid solubility changes with temperature. For example, the solid solubility of silicon and manganese in aluminum is relatively small and does not change much with temperature. Although magnesium and zinc have greater solid solubility in aluminum-based solid solution, the structure and matrix of the compound formed by them and aluminum The difference is not big and the strengthening effect is minimal.