(中南大學(xué) 材料科學(xué)與工程系， 長沙 410083)
摘 要: 采用了在-193 ℃長時間保溫，緩慢升溫到150 ℃的深冷處理工藝，對1～8系的12種常用鋁合金進(jìn)行處理。研究發(fā)現(xiàn)，深冷處理可以提高1230, 2017, 2024, 3003, 4032, 7075和8009合金的室溫拉伸強(qiáng)度，但其塑性有所下降；深冷處理對2618和5254合金的室溫力學(xué)性能影響不大，但降低了6063合金的室溫拉伸強(qiáng)度，提高了它的塑性。對上述常用鋁合金深冷處理前后的XRD衍射圖譜研究表明，深冷處理可以使得這些合金某些衍射晶面上的衍射強(qiáng)度發(fā)生明顯的變化。研究了二次深冷處理對1230,7075和8009合金力學(xué)性能的影響以及深冷處理對8009合金高溫性能影響。對鋁合金深冷處理的機(jī)理進(jìn)行了探討，并提出了深冷處理的收縮效應(yīng)和晶粒轉(zhuǎn)動效應(yīng)。
關(guān)鍵字: 鋁合金； 深冷處理； 晶粒轉(zhuǎn)動
（Department of Materials Science and Engineering，Central South University, Changsha 410083， P.R.China）
Abstract:The effect of cryogenic treatment on the microstructure and properties of twelve kinds of commercial Al alloys at -193 ℃ for 24 h wasinvestigated preliminary. The results show that cryogenic treatment can improve the room temperature strength of 1230, 2017, 2024, 3003, 4032, 7075 and8009 alloy but reduce the ductility of these alloys； there is not obvious change i, n 5254 and 2618 alloy； the room temperature strength of 6063 alloy is decreased but the ductility improved. The XRD crystallograms before and after cryogenic treatment of these alloys were studied. It reveals that the cryogenic treatment can change the diffraction peak intensity of some crystal planes in these alloys. Finally, the effect of cryogenic treatment on the elevated temperature properties of 8009 alloy at 350 ℃ and the effect of twice cryogenictreatment on the properties of 1230, 7075 and 8009 alloy were investigated. Mechanism of cryogenic treatment of Al alloys was discussed with volume shrinkage and crystal plan turn.
Key words: Al alloys； cryogenic treatment； turnof crystal plane
