(北京有色金屬研究總院 有色金屬材料制備加工國(guó)家重點(diǎn)實(shí)驗(yàn)，北京 100088)
摘 要: 利用差示量熱法(DSC)、透射電鏡(TEM)、選區(qū)電子衍射(SAED)、常規(guī)力學(xué)性能測(cè)試等手段研究了7B04鋁合金時(shí)效沉淀析出及強(qiáng)化行為。結(jié)果表明：該材料存在顯著的自然時(shí)效現(xiàn)象，大量的GPⅠ區(qū)沉淀析出是自然時(shí)效強(qiáng)化的主要原因；合金在120 ℃進(jìn)行人工時(shí)效的初期析出大量GP區(qū)，使材料的強(qiáng)度迅速提高，時(shí)效8 h后，其橫向極限抗拉強(qiáng)度即可達(dá)到570 MPa，時(shí)效22 h時(shí)可達(dá)強(qiáng)度峰值點(diǎn)，此時(shí)GP區(qū)(包括GPⅠ和GPⅡ區(qū))和η′相是主要強(qiáng)化相；峰值時(shí)效后繼續(xù)延長(zhǎng)時(shí)效時(shí)間，材料的強(qiáng)度無(wú)明顯降低，極限抗拉強(qiáng)度保持在590 MPa左右。
關(guān)鍵字: 7B04鋁合金；時(shí)效；沉淀析出；強(qiáng)化行為
behavior of 7B04 aluminum alloy
WANG Feng, LIU Hong-wei
（State Key Laboratory for Fabrication and Processing of Nonferrous Metals,
General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract:The ageing precipitation and strengthening behavior of 7B04 aluminum alloy were investigated by DSC, TEM, HREM, SAED and tensile testing techniques. The results show that increment of strength during natural ageing at room temperature is related to the dominant formation of GPI zones. During the early stage of artificial ageing at 120 ℃, the strong age-strengthening response is due to the precipitation of GP (both GPI and GPII) zones. The peak UTS value is achieved as 570 MPa after ageing at 120 ℃ for 22 h, both GP (GPⅠ and GPⅡ) zones and η′ phase are major precipitates at this stage. After 22 h, the tensile strength changes little (approximate by at 590 MPa) for a relative long time.
Key words: 7B04 aluminum alloy; ageing; precipitation; strengthening behavior
