析出型 高强度 輕合金材料에 있어서 過時效와 2段時效의 影響 = The effect of over-ageing and two-step ageing in the precipitation type of High-Strength Light Alloys.

다국어 초록 (Multilingual Abstract)

The Ageing characteristics resulted by the over-ageing and the two-step ageing precipitation hardening of the precipitation-type high strength light alloy Al-Zn-Mg containing a small amount of Cu and Zr has been investigated.
We studied the strength and elongation using ,Instron at the same hardness of the primary zone and over-ageing zone in the age hardness curve.
We used the 1mm/min cross-head speed. The results are as follows
1. Both age hardening velocity and maximum hardness value turned out to be high.
2. We obtained an excellent: material with tensile strength over 40kg/mm2 and elongation more than 16%
3. There is an effect that over ageing zone has an increasing elongation and a decreasing strength than the primary zone as the temperature increases.
4. By two step ageing, H,. increase no more than the value of the one step ageing.
5. Simple ageing procedure is good for high ageing temperature. Even when they were changed into the state of two
step ageing, it did not show any minus effect.

목차 (Table of Contents)

• Ⅰ. 序論
• Ⅱ. 試料및 實驗方法
• Ⅲ. 實驗結果및 考察
• 1. 1段時效 溫度의 影響
• 2. 適時效에 對한 强度와 延伸率의 影響
• 3. 2段時效 溫度의 影響
• 4. 1段時效와 2段時效의 比較
• Ⅳ. 結論