Effect of minor Sc and Zr on microstructure and mechanical properties of Al-Zn-Mg-Cu alloy

1 Introduction The microstructure and properties of aluminium alloys are strongly affected by adding small quantities of scandium. Minor Sc may improve the temperature of recrystallization and fracture toughness, decrease the sensitivity of stress corrosi…     

含钪Al-Cu-Li合金氩弧焊接头组织与性能

为了探索新型含钪Al-Cu-Li-Zr合金板材的焊接接头性能,采用氩弧焊接工艺对该合金的T6峰时效态板材进行了焊接.采用室温拉伸力学性能试验、金相显微镜和透射电镜研究了焊缝的显微组织和力学性能之间的关系.结果表明,在氩弧焊条件下,采用钪与锆、锰等多组元复合微合金化焊丝对含钪Al-Cu-Li-Zr合金板材进行焊接,焊接接头的强度系数达到65%,拉伸试验断口发生在热影响区内,微量钪对焊接接头具有晶粒细化强化作用和直接析出强化作用.     

Effects of minor Sc and Zr additions on mechanical properties and microstructure evolution of Al−Zn−Mg−Cu alloys

The effects of minor Sc and Zr additions on the mechanical properties and microstructure evolution of Al−Zn−Mg−Cu alloys were studied using tensile tests, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The ultimate tensile strength of the peak-aged Al−Zn−Mg−Cu alloy is improved by about 105 MPa with the addition of 0.10% Zr. An increase of about 133 MPa is observed with the joint addition of 0.07% Sc and 0.07% Zr. For the alloys modified with the minor addition of Sc and Zr (0.14%), the main strengthening mechanisms of minor addition of Sc and Zr are fine-grain strengthening, sub-structure strengthening and the Orowan strengthening mechanism produced by the Al₃(Sc,Zr) and Al₃Zr dispersoids. The volume of Al₃Zr particles is less than that of Al₃(Sc,Zr) particles, but the distribution of Al₃(Sc,Zr) particles is more dispersed throughout the matrix leading to pinning the dislocations motion and restraining the recrystallization more effectively.     

Effect of minor Zr and Sc on microstructures and mechanical properties of Al–Mg–Si–Cu–Cr–V alloys

The effects of minor contents of Zr and Sc on the microstructures and mechanical properties of Al–Mg–Si–Cu–Cr–V alloy were studied. The results show that the effects of minor Zr and Sc on the as-cast grain refinement in the ingots, the improvement in the strength of the as-extruded alloys and the restriction of high angle grain boundaries in the aged alloys can be sorted as Al₃Sc>Al₃(Zr,Sc)>Al₃Zr. None of them could stop the nucleation of recrystallization, but Al₃(Zr,Sc) phase is a more effective inhibitor of dislocation movement compared to Al₃Sc in the aged alloys. Compared with the mechanical properties of the aged alloy added only 0.15% Sc, the joint addition of Zr and Sc to the alloy leads to a very slight decrease in strength with even no cost of ductility. Taking both the production cost and the little bad influence on mechanical properties into consideration, an optimal content of Zr and Sc in the Al–Mg–Si–Cu–Cr–V alloy to substitute 0.15% Sc is 0.13% Zr+0.03% Sc.     

稀土元素对新型Al-Mg合金焊接接头组织和性能的影响

研究了Sc,Zr元素对新型Al-Mg合金焊接接头组织和性能的影响。建立了MIG电弧二维数值分析模型,模拟出电弧温度场的分布情况,电弧最高温度超过20 000 K,且温度分布存在较大的温度梯度,说明高温电弧对合金有益元素有一定的烧损作用。采用合金元素不同的焊丝ER5356,ER5B06和ER5B71作为填充材料,对2 mm厚新型Al-Mg合金进行MIG焊接试验,研究高Mg焊丝添加不同稀土元素对焊接性能及组织的影响。结果表明,使用3种焊丝均可获得性能优良的焊接接头,使用ER5B06焊丝的接头力学性能得到一定提升,但焊缝晶粒细化效果不明显;使用复合添加Sc,Zr微量元素的ER5B71焊丝,接头晶粒能够有效细化,力学性能进一步得到提升。3种焊丝中,采用ER5B71焊丝的焊接接头强度最高,焊接系数为83%,焊接接头中起到细化晶粒作用的析出相以Al3(Sc,Zr)为主。同时,无论采用哪种焊丝,焊接热影响区未发生明细的晶粒粗化,说明在母材中加入一定的Sc,Zr微量元素,可提升合金材料抗软化能力,有效抑制热影响区再结晶行为。 创新点： 采用电弧物理数值模拟和进行试验结合的方法,进行研究论证,使研究内容充实,有理论深度,更具说服力;选择具有稀土元素的铝合金和焊丝作为研究对象,对新材料及焊材的研发具有一定指导意义。     

960 MPa高强钢金属粉芯型药芯焊丝焊缝金属韧化机理

针对960 MPa高强钢研制了以Mn,Ni,Mo和Cr元素为主要合金体系,以Ti,B,Nb和Al元素为微合金元素的金属粉芯型药芯焊丝. 采用熔化极气体保护焊进行施焊,通过拉伸试验和低温冲击试验等方法对接头力学性能进行了测试,结合金相组织观察、断口扫描、能谱分析和透射电镜观察等对合金元素的作用机理进行了分析. 结果表明,接头抗拉强度平均值为952.24 MPa,-20 ℃焊缝低温冲击吸收功平均值为70 J,研制的焊丝在保证接头强度的同时有效改善了焊缝金属的低温冲击吸收功. 在药芯成分中,主要合金元素起固溶强化和弥散强化作用,微合金元素通过细化晶粒、抑制块状铁素体析出和增加针状铁素体形核率等方式改善低温冲击性能.     

Microstructures and mechanical properties of Al-Mg and Al-Zn-Mg based alloys containing minor scandium and zirconium

1　INTRODUCTIONAddingofminorMn ,Cr ,Ti,B ,Zr ,Sc ,Agintoaluminumalloyscanremarkablychangethemi crostructuresandpropertiesofaluminumalloys[18] .Amongthem ,theeffectofminorScandZrhasre ceivedspecialattention .Onthe 1stInternationalScandiumConferenceheldinMoscowin 1994 ,Rus sianmetallurgistsdescribedtheapplicationprospectofaluminumalloyscontainingScinaerospace ,aviation ,warshipsandnuclearindustry ,whichhasstimulatedmanyindustrialcountries’researchinterestinthiskindofalloys .Atpresent…     

Effects of minor Sc on the microstructure and mechanical properties of Al-Zn-Mg-Cu-Zr based alloys

Five kinds of Al-Zn-Mg-Cu-Zr based alloys with different Sc additions were prepared by ingot metallurgy. The effects of minor Sc on the microstructure and mechanical properties of Al-Zn-Mg-Cu-Zr based alloys were investigated using tensile tests, optical microscopy (OM), and transmission electron microscopy (TEM). The results show that the ultimate tensile strength and yield strength are improved by 94 and 110 Mpa, respectively, and the elongation to failure remains at a reasonable extent (11.1%) in the Al-Zn-Mg-Cu-Zr based alloy with 0.21 wt.% Sc addition after solution heat treatment at 475℃ for 40 min and then aged at 120℃ for 24 h. The addition of minor Sc induces the formation of Al3(Sc,Zr) particles, which are highly effective in refining the cast microstructures, retarding recrystallization, and pinning dislocations. The increment of strength is attributed mainly to fine grain strengthening, precipitation strengthening of Al3(Sc,Zr) particles, and substructure strengthening.     

Al3(Sc1-xZrx)纳米粒子对搅拌摩擦焊Al-Mg-Mn合金显微组织和力学性能的影响(英文)

通过拉伸测试和显微分析方法研究搅拌摩擦焊Al-5.50Mg-0.45Mn和Al-5.50Mg-0.45Mn-0.25Sc-0.10Zr(质量分数,%)合金的显微组织和力学性能。结果表明,Al-Mg-Mn接头的屈服强度、抗拉强度和伸长率分别为(191±3) MPa、(315±1) MPa和(4.8±1.9)%,Al-Mg-Mn-Sc-Zr接头的分别为(288±5) MPa、(391±2) MPa和(3.4±1.0)%。相比Al-Mg-Mn接头,Al-Mg-Mn-Sc-Zr接头晶粒更细小、平均取向差角更低、小角度晶界百分数更高。两种接头的断裂位置均位于焊核区(WNZ),在该“最薄弱微区”内,Al₃(Sc_1-xZr_x)纳米粒子的平均尺寸为(9.92±2.69) nm,可提供有效奥罗万和晶界强化,使Al-Mg-Mn接头的屈服强度提高97 MPa。     

固溶处理对Al-9.0Zn-2.8Mg-2.5Cu-0.12Zr-0.03Sc铝合金组织性能的影响

采用金相显微镜、差热分析(DSC)和透射电镜(TEM)研究复合添加0.03%Sc 与0.12%Zr 及固溶处理对Al?9.0Zn?2.8Mg?2.5Cu合金组织性能的影响,以及添加少量(小于0.1%)的Sc是否能得到高性能铝合金。结果表明：添加0.03%Sc与0.12%Zr可以使Al?9.0Zn?2.8Mg?2.5Cu合金出现“花瓣状”的Al3(Sc,Zr)析出相;Al3(Sc,Zr)粒子对位错有强烈的钉扎作用,明显抑制 Al?9.0Zn?2.8Mg?2.5Cu 合金在均匀化和挤压过程中的再结晶;多级固溶明显优于单级固溶,可以在添加少量Sc(小于0.1%)时,避免Al?9.0Zn?2.8Mg?2.5Cu发生再结晶：(420°C,3 h)+(465°C,2 h)为最佳固溶条件,此时Al?9.0Zn?2.8Mg?2.5Cu?0.12Zr?0.03Sc合金的抗拉强度为777.29 MPa,伸长率为11.84%。     

焊丝成分对铝/铜激光熔钎焊接头组织和性能的影响

通过添加Zn-Al焊丝成功实现了2A16铝合金/T2铜异种材料的激光熔钎焊连接,并采用扫描电子显微镜和能谱仪对接头的微观组织进行表征,同时,研究了Zn-2％Al,Zn-5％Al和Zn-10％Al?3种焊丝对接头成形、微观组织以及力学性能的影响.结果表明,铝/铜激光熔钎焊接头主要由CuZn相,Al2Cu相,Al4Cu9相...     

微量Sc和Zr对Al-Mg-Mn合金组织与力学性能的影响

采用活性熔剂保护熔炼、水冷铜模激冷铸造制备Al-5.8Mg-0.4Mn和Al-5.8Mg-0.4Mn-0.25Sc-0.1Zr(质量分数,%)两种合金铸锭。合金铸锭经热轧中间退火冷轧成2 mm薄板;研究稳定化退火及微量Sc和Zr对Al-Mg-Mn合金组织与性能的影响。结果表明:在Al-Mg-Mn合金中加入微量Sc和Zr后形成大量弥散的Al3(Sc,Zr)粒子,这些粒子对位错和亚晶界具有强烈的钉扎作用,能明显提高合金的抗再结晶能力和室温力学性能;Al-Mg-Mn-Sc-Zr合金板材经300℃退火1 h后可获得最佳综合力学性能,其σb、σ0.2与δ分别为436 MPa、327 MPa和16.7%。     

微量Cr、Mn、Zr、Ti、B元素对铸态AlZnMgCu合金的晶粒细化效果的影响

采用光学显微镜、扫描电镜和能谱分析仪考察了Cr、Mn、Zr、Ti、B的联合加入对AlZnMgCu合金的晶粒细化效果。结果发现在铸态合金中同时加入Cr-Mn-Ti-B时晶粒尺寸由256 μm 降为102 μm。而当联合加入Ti-Zr-B后能产生更加强的细化效果,晶粒平均尺寸降为55 μm。这是因为Cr、Mn原子簇团有利于促进Al3Ti形核并成为其结晶基底。当联合加入Cr、Mn、Zr、Ti、B时则可产生更加明显的晶粒细化效果,平均晶粒尺寸变为22 μm。这是因为富Cr、Mn原子簇团在成为Al3Ti结晶核心后,部分Zr原子置换了其中的Ti原子形成了新的Al3(Tix, Zr1-x)结晶核心。而过渡族金属Cr、Mn还能降低液体金属和Al3Ti和Al3(Tix, Zr1-x)的表面张力,抑制结晶核心的长大。     

Microstructure and mechanical properties of Cu/Al joints brazed using (Cu,Ni, Zr,Er)-modified Al—Si filler alloys

To design a promising Al—Si filler alloy with a relatively low melting-point, good strength and plasticity for the Cu/Al joint, the Cu, Ni, Zr and Er elements were innovatively added to modify the traditional Al—Si eutectic filler. The microstructure and mechanical properties of filler alloys and Cu/Al joints were investigated. The result indicated that the Al—Si—Ni—Cu filler alloys mainly consisted of Al(s,s), Al₂(Cu,Ni) and Si(s,s). The Al—10Si—2Ni—6Cu filler alloy exhibited relatively low solidus (521 °C) and liquidus (577 °C) temperature, good tensile strength (305.8 MPa) and fracture elongation (8.5%). The corresponding Cu/Al joint brazed using Al—10Si—2Ni—6Cu filler was mainly composed of Al₈(Mn,Fe)₂Si, Al₂(Cu,Ni)₃, Al(Cu,Ni), Al₂(Cu,Ni) and Al(s,s), yielding a shear strength of (90.3±10.7) MPa. The joint strength was further improved to (94.6±2.5) MPa when the joint was brazed using the Al—10Si—2Ni—6Cu—0.2Er—0.2Zr filler alloy. Consequently, the (Cu, Ni, Zr, Er)-modified Al—Si filler alloy was suitable for obtaining high-quality Cu/Al brazed joints.     

Effect of minor Sc and Zr on microstructures and mechanical properties of Al-Zn-Mg based alloys

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Al-Mg-Mn-Sc-Zr合金板材搅拌摩擦焊和氩弧焊焊接接头的对比

研究Al-Mg-Mn-Sc-Zr合金的焊接工艺和焊接接头组织和性能。采用搅拌摩擦焊（FSW）和氩弧焊（TIG）2种焊接工艺对该合金的热轧和冷轧-退火2种使用态板材进行焊接。采用比较研究的方法测定和研究焊接接头的力学性能和显微组织,利用光学显微镜和透射电子显微镜研究焊缝的显微组织和力学性能之间的关系。结果表明,与基材相比,Al-Mg-Mn-Sc-Zr合金的热轧和冷轧-退火板材的FSW和TIG焊接接头的强度均下降,但FSW焊接系数高于TIG焊接系数。这是因为FSW焊接接头焊核区亚结构强化的丧失和Al3（Sc,Zr）的析出强化作用的极少量丧失,而TIG焊焊接接头的软化主要原因是其形变强化的完全丧失和Al3（Sc,Zr）的析出强化作用的大部分丧失,且搅拌摩擦焊焊核区晶粒比TIG焊的焊缝区晶粒更细小。     

Effect of trace Sc and Zr on aging behavior and tensile properties of 2618 alloy

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Mechanical Properties and Microstructure of TIG and FSW Joints of a New Al-Mg-Mn-Sc-Zr Alloy

A new Al-5.8%Mg-0.4%Mn-0.25%Sc-0.10%Zr (wt.%) alloy was successfully welded by tungsten inert gas (TIG) and friction stir welding (FSW) techniques, respectively. The mechanical properties and microstructure of the welded joints were investigated by microhardness measurements, tensile tests, and microscopy methods. The results show that the ultimate tensile strength, yield strength, and elongation to failure are 358, 234 MPa, and 27.6% for TIG welded joint, and 376, 245 MPa and 31.9% for FSW joint, respectively, showing high strength and superior ductility. The TIG welded joint fails in the heat-affected zone and the fracture of FSW joint is located in stirred zone. Al-Mg-Mn-Sc-Zr alloy is characterized by lots of dislocation tangles and secondary coherent Al₃(Sc,Zr) particles. The superior mechanical properties of the TIG and FSW joints are mainly derived from the Orowan strengthening and grain boundary strengthening caused by secondary coherent Al₃(Sc,Zr) nano-particles (20-40 nm). For new Al-Mg-Mn-Sc-Zr alloy, the positive effect from secondary Al₃(Sc, Zr) particles in the base metal can be better preserved in FSW joint than in TIG welded joint.     

微量Sc对2195铝锂合金应变时效态的显微组织和力学性能的影响

采用拉伸试验机、光学金相显微镜、透射电镜、扫描电镜等设备研究了添加微量Sc对2195铝锂合金应变时效态的显微组织和拉伸性能的影响。结果表明：微量Sc加入后能生成细小弥散Al3(Sc，Zr)质点，起到抑制再结晶的作用；微量Sc的加入既促使合金晶内析出的T1相分布更弥散均匀，又能使亚晶界和晶界上析出的T1相变得细小，几乎不出现明显的晶界无析出带，因而可在不降低合金强度的前提下有效地改善其塑性。     

Effect of Zr and Sc on mechanical properties and electrical conductivities of Al wires

In order to obtain the Al wires with good mechanical properties and high electrical conductivities, conductive wires of Al–0.16Zr, Al–0.16Sc, Al–0.12Sc–0.04Zr (mass fraction, %) and pure Al (99.996%) were produced with the diameter of 9.5 mm by continuous rheo-extrusion technology, and the extruded materials were heat treated and analyzed. The results show that the separate additions of 0.16% Sc and 0.16% Zr to pure Al improve the ultimate tensile strength but reduce the electrical conductivity, and the similar trend is found in the Al–0.12Sc–0.04Zr alloy. After the subsequent heat treatment, the wire with the optimum comprehensive properties is Al–0.12Sc–0.04Zr alloy, of which the ultimate tensile strength and electrical conductivity reach 160 MPa and 64.03% (IACS), respectively.