(1. Department of Metallurgical Engineering,
Chonbuk University, 664-14 ducjin-dong ducjin-ku,
chn-ju 561-756, Korea;
2. Department of Metallurgical Engineering,
Chonbuk National University, 664-14 ducjin-dong
ducjin-ku,Chon-ju 561-756, Research Institute of
Advanced Materials Development, Korea)
摘 要: 對(duì)添加微量Sb元素的4XXX系列鋁合金的鑄造、擠壓及鍛造顯微組織進(jìn)行了觀察。結(jié)果表明：鑄造狀態(tài)下的樹(shù)枝狀組織在擠壓預(yù)熱過(guò)程中形成了帶有方向性的小結(jié)晶，之后再成長(zhǎng)為顯微結(jié)晶，觀察到了變化為球狀的結(jié)晶粒。鍛造后，α相基體中除了共晶組成(11%～12.6%Si)外，還存在多角形初晶Si和Al4Cu9相。正是這些相的存在，提高了合金的高溫強(qiáng)度。在凝固過(guò)程中，由于Mg的部分偏析，認(rèn)為能析出Mg2Si，有助于提高材料的耐熱性能，并判斷Al4Cu9相起維持高溫強(qiáng)度的重要作用。用該材料制造的汽車(chē)連桿的平均硬度為Hv133，大體上能夠滿(mǎn)足實(shí)際需要(Hv137)。隨著鍛造溫度的增加，變形抗力和加工應(yīng)力減小，合金的成形性能得到提高。
關(guān)鍵字: 成形性能；擠壓；連桿；鍛造
Al alloys
（1. Department of Metallurgical Engineering,
Chonbuk University, 664-14 ducjin-dong ducjin-ku,
chn-ju 561-756, Korea;
2. Department of Metallurgical Engineering,
Chonbuk National University, 664-14 ducjin-dong
ducjin-ku,Chon-ju 561-756, Research Institute of
Advanced Materials Development, Korea）
Abstract:The microstructures of as-cast, extruded and forged 4XXX series Al alloy with addition of Sb were observed. The results show that dendrites in casting are converted into directional micro-crystals, and then recrystallize and grow into spheroidizing grains. After forging, in α-phase, polygonal proeutectic Si and Al4Cu9 are observed in addition to eutectic s(11%～12.6% Si). It is thought that proeutectic Si will improve the heat-resistance by forming Mg2Si with Mg, and that Al4Cu9 will play an important role in maintaining the high temperature strength of the alloy. The average hardness of connecting-rod prepared by this material is Hv133, that almost satisfies the requirement. With the increase of forging temperature, the deformation resistance and stress for working are decreased, which brings about the improvement of formability.
Key words: formability; extrusion; connecting-rod; forging
