水平流動狀況
( 1. 蘭州理工大學 甘肅省有色金屬新材料國家重點實驗室，
蘭州 730050;
2. 中國南車集團四方機車車輛股份有限公司， 青島 266031)
摘 要: 通過在10 mm厚LF2鋁合金板的不同位置嵌入示蹤Fe粉， 進行攪拌摩擦焊對接實驗， 焊后截取不同深度的水平面試樣， 采用掃描電鏡對試樣進行能譜分析， 通過觀察Fe粉在焊縫金屬中的水平分布， 確定了10 mm厚LF2攪拌摩擦焊焊縫金屬的二維水平流動狀況。結(jié)果表明， 塑性金屬流動關(guān)于焊縫中心并不對稱。 焊縫下部金屬受攪拌針作用， 前進側(cè)大部分金屬與焊接方向相反向后流動， 小部分金屬向前流動， 但都未進入返回側(cè)；返回側(cè)金屬都向后流動， 且有部分金屬進入前進側(cè)。 焊縫上部金屬主要受軸肩作用， 前進側(cè)大部分金屬向前流動但未進入返回側(cè)， 小部分金屬向后流動； 返回側(cè)金屬沿旋轉(zhuǎn)方向流入前進側(cè)。
關(guān)鍵字: 攪拌摩擦焊； 流場； 前進側(cè)； 返回側(cè)； 示蹤粒子
（ 1. State Key Laboratory of Advanced Non-ferrous Metal Materials，
Gansu Province，Lanzhou University of Technology，Lanzhou 730050，China;
2. Sifang Locomotive & Rolling Stock Ltd.，CSR，Qingdao 266031,China）
Abstract: Marker Fe grains were inserted into 10 mm LF2 aluminum alloy in different positions during the friction stir welding course. After butt welding， the samples which were selected in horizontal sections in different depths were analyzed by using EDS(energy dispersive X-ray spectroscopy) of SEM(scanning electron microscope). The 2-D horizontal flow status of friction stir welding for 10 mm LF2 aluminum alloy was confirmed by observing the horizontal distributions of Fe grains in welding zone. The results show that the flow is not symmetric about the weld centerline. The lower metal of weld is completely affected by pin. The bulk of metal in the advancing side is transported backward against the welding direction. However，a small amount is moved forward at the edge of the pin. The metal in the retreating side is only transported against the welding direction and some metal flows into the advancing side. The upper metal of weld is mainly affected by shoulder. The bulk of metal in the advancing side moves forward in the welding direction and a little backward； but no metal flows into the retreating side. However，the bulk of metal in the retreating side is transported backward into the advancing side along the rotation direction.
Key words: friction stir welding；flow field；advancing side；retreating side；marker grain
