Zr在7050铝合金中的行为与作用的电镜观察

本文研究了含Zr的高强7050铝合金中Zr化合物的存在形态,尺寸和分布特点。TEM观察表明,锭铸中的Zr以ZrAl_3初晶和固溶体两种形式存在;均匀化处理的铸锭中,球形的ZrAl_3在基体上呈共格与非共格形式弥散析出,尺寸约为10～30nμ,热轧变形后,ZrAl_3大都钉轧在位错线和小角晶界上,其形态和尺寸没有明显改变;淬火后,可观察到大量存在的亚结构和亚晶粒,球形ZrAl_3质点分布在亚晶界、晶内以及位错线上,非共格的ZrAl_3周围有η相非均质成核;与含Cr的该系合金相比较,可看到E相尺寸远大于含Zr合金中的ZrAl_3质点,而ZrAl_3周围非均质成核的η相的尺寸和数量要比E相周围的小得多;淬火后经时效和双级过时效热处理,ZrAl_3质点的形态、尺寸和分布,均无显著变化。利用上述实验结果,可以园满地解释Zr对7050铝合金细化晶粒、提高再结晶温度、降低淬火敏感性以及提高强度和抗应力腐蚀性能的作用。

TEM Observation on Behaviour and Action of Zirconium in 7050 Aluminium-Alloy

This paper discusses the shape,size and distribution of zirconium cmpounds in the high-strength zirconium-containing 7050 aluminium alloy, It, especially. introduces the ZrAl_3 particle, its forms in cast ingots and changes in homogeneous treatment, its location,shape,and size in hot rolled slabs,and its changes in slabs quenched and aging treated. The experimental results obtained can be used to explain the action of Zr in the refined grain size,the increased recrystallization temperature,the lowered quenching susceptibility and the increased strength and stress corrosion resistance in the alloy,