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1.
微量Sc对Al-Cu-Li-Zr合金的微观组织和拉伸性能的影响   总被引:3,自引:1,他引:2  
研究了微量Sc对Al-Cu-Li-Zr合金微观组织和拉伸性能的影响.结果表明:添加0.1%Sc(质量分数,下同)能消除铸态合金的枝晶组织,细化合金的晶粒.合金铸锭在随后的均匀化和热加工加热过程中,析出细小、弥散的次生Al3Sc质点,这种质点强烈地钉扎合金中的位错和亚晶界,从而有效地抑制合金的再结晶,具有亚结构强化和直接析出强化作用.加入微量Sc后,Al-Cu-Li-Zr合金的强度大大提高,并且合金的塑性也得到明显改善.  相似文献   

2.
Sc和Zr复合微合金化对Al-Zn-Mg-Cu合金组织与性能的影响   总被引:4,自引:0,他引:4  
采用水冷铜模一激冷铸造法,制备了三种Sc和Zr含量不同的Al-Zn-Mg-Cu合金薄板材,测试了合金经120℃时效不同时间后的拉伸性能,利用光学显微镜和透射电子显微镜观察了合金的显微组织。结果表明:采用Sc和Zr复合微合金化可明显细化合金的铸态晶粒组织,抑制合金的再结晶,大大提高合金的强度;Sc含量越高,晶粒细化效果越好,合金强度提高也越大;微量Sc和Zr在Al-Zn-Mg-Cu合金中主要以Al3(Sc,Zr)质点的形式存在,初生Al3(Sc,Zr)粒子是在合金凝固过程中形成的,主要起非均质形核的作用,次生Al3(Sc,Zr)粒子是合金在均匀化处理和后续热处理中析出的,起亚结构强化和直接析出强化作用。  相似文献   

3.
微量钪对Al-Cu-Li-Mg-Zr合金组织与性能的影响   总被引:1,自引:0,他引:1  
通过显微组织观察和室温拉伸试验,研究了微量Sc对Al-Cu-Li-Mg-Zr合金组织和拉伸性能的影响。结果表明,在Al-Cu-Li-Mg-Zr合金中加入微量Sc,可消除铸态枝晶组织并显著细化铸态晶粒、有效抑制再结晶,明显提高了合金的强度和塑性。微量Sc引起的强化来源于晶粒细化、次生的Al3(Sc,Zr)相析出和亚结构强化。  相似文献   

4.
添加微量Sc、Zr对超高强铝合金微观结构和性能的影响   总被引:1,自引:0,他引:1  
采用低频电磁铸造技术制备Al-9Zn-2.8Mg-2.5Cu-x Zr-y Sc(x=0,0.15%,0.15%;y=0,0.05%,0.15%)合金,借助金相显微镜、扫描电镜、透射电镜、力学性能测试等手段分别对其均匀化、热挤压态、固溶态和时效态的组织与性能进行对比分析。结果表明:添加微量Sc和Zr,会在凝固过程中形成初生Al3(Sc,Zr),可显著细化合金铸态晶粒;均匀化时形成的次生Al3(Sc,Zr)粒子可以强烈钉扎位错和亚晶界,有效抑制变形组织的再结晶,显著提高合金的力学性能。与不含Sc、Zr的合金相比,含0.05%Sc和0.15%Zr的合金经固溶处理和峰值时效处理后其抗拉强度和屈服强度分别提高172 MPa和218 MPa,其强化作用主要来自含Sc、Zr化合物对合金起到的亚结构强化、析出强化和细晶强化。  相似文献   

5.
研究了在5A01合金基础上添加0.2%Sc和0.3%Sc后合金的显微组织、力学性能、腐蚀性能及焊接性能。结果表明,微量Sc的加入,初生Al3Sc或Al3(Sc,Zr)粒子可成为有效的非均质晶核,细化合金的铸态晶粒,次生Al3Sc或Al3(Sc,Zr)粒子能有效地钉扎位错和亚晶界,稳定亚结构并强烈抑制合金的再结晶。因此,微量Sc加入使5A01合金基体强度提高,腐蚀性能和焊接性能与5A01合金相当甚至更好。  相似文献   

6.
Al-Mg-Sc合金铸态组织观察   总被引:7,自引:1,他引:6  
采用金相显微镜、扫功电镜(SEM),观察了微量Sc(钪)对Al-Mg合金显微组织和第二相粒子形貌的影响,试验结果表明,普通Al-Mg合金添加微量Se后其铸态组织得到显著细化,随着Mg,Se含量增加,合金的组织随之细化。第二相粒子形态表现多样,对第二相粒子成分分析结果表明它是含Al,Sc,Zr,Ti的复合粒子。  相似文献   

7.
研究了温度、时间等因素对Al-0.4Sc合金时效过程中次生Al3Sc粒子的析出和长大规律及其对合金性能的影响。指出在350、400和450℃下时效,次生Al3Sc粒子长大行为基本符合Lifshitz-Slyozov-Wagner(LSW)理论预测;在500℃下时效1h,粒子长大行为接近LSW理论预测值,1h以上,粒子长大速度变慢,与LSW理论偏差较大。当Al3Sc粒子半径在4~40nm的范围内,Al-0.4Sc合金硬度值随着粒子尺寸上升而下降;当Al3Sc半径为4~7.5nm时,硬度为750~850MPa,大约是热处理前的硬度值(200MPa)的3.75~4.25倍,析出强化作用显著;当Al3Sc半径达到40nm时,合金硬度下降到300MPa。  相似文献   

8.
用金相显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)及显微硬度仪研究了Sc含量对Al-5.5Mg-0.5Mn-XSc-0.1Zr (质量分数,%) (0.05≤X≤0.50)合金铸态显微组织和时效处理后二次析出相的形貌及其强化作用的影响。结果表明:当Sc含量少于0.09%(质量分数,下同)时,凝固过程中无含Sc相析出,铸锭组织为柱状树枝晶,时效后强化作用有限;当Sc含量在0.16%~0.23%时,凝固过程中析出少量初生及共晶Al3(Sc, Zr)相,这既能够细化晶粒,又不影响时效后二次析出相的热稳定性,时效后合金的硬度也较高;而Sc含量过高(X≥0.23)时,合金中初生和共晶Al3(Sc, Zr)相的含量增多,虽然也能够细化晶粒,但凝固后基体中固溶的Zr含量也会随之降低,导致二次Al3(Sc, Zr)相的热稳定性降低,450 ℃时效24 h后二次析出相粗化严重,强化作用很弱  相似文献   

9.
采用拉伸和疲劳力学性能测试、金相和透射电子显微分析,研究2524和用微量Sc和Zr合金化的2524SZ合金T3态薄板的组织和性能,考察微量Sc和Zr合金化对2524SZ合金T3态薄板疲劳裂纹扩展特性的影响。结果表明:微量Sc和Zr在2524SZ合金中主要以次生的Al3(Sc,Zr)粒子形式存在,这种粒子与基体共格,固溶处理过程中能部分抑制合金的再结晶,基体晶粒组织主要由细小的亚晶组成;在相近的应力强度因子ΔK条件下,2524和2524SZ合金T3态薄板的疲劳裂纹扩展速率分别为4.50和2.35μm/cycle,表明添加微量Sc和Zr能显著降低2524SZ合金抵抗疲劳裂纹扩展速率;亚晶强化和Al3(Sc,Zr)相析出强化是微量Sc和Zr使2524SZ合金疲劳裂纹扩展速率降低的主要原因。  相似文献   

10.
采用电子拉伸实验机、金相显微镜、扫描电镜及透射电镜,研究了单辊搅拌冷却技术(Shearing-Cooling-Rolling,简称SCR)成形Al-3Mg-0.4Sc合金线材的组织与性能。结果表明:经SCR成形的合金线材晶粒组织非常细小,Sc主要以初生Al3Sc粒子和次生Al3Sc粒子存在。初生Al3Sc粒子是在SCR成形中凝固形成的,作为非均质晶核细化合金晶粒。次生Al3Sc粒子是合金在热处理过程中沉淀析出的,有效钉扎位错和亚晶界,抑制合金再结晶。d5.9mm合金线材320℃时效2h的抗拉强度为425MPa,延伸率为19.8%。SCR成形Al-3Mg-0.4Sc合金具有较高强度的主要原因有两个:1)SCR成形单辊剪切细化晶粒和初生Al3Sc粒子作为非均质晶核细化晶粒共同作用所产生的细晶强化;2)适当热处理过程中沉淀析出的细小、弥散的Al3Sc强化相粒子的沉淀强化。  相似文献   

11.
Atomic bonding and mechanical properties of Al-Mg-Zr-Sc alloy   总被引:5,自引:0,他引:5  
The valence electron structures of AI-Mg alloy with minor Sc and Zr were calculated according to the empirical electron theory(EET) in solid. The results show that because of the strong interaction of AI atom with Zr and Sc atom in melting during solidification, the Al3 Sc and Al3 (Sc1-xZrx) particles which act as heterogeneous nuclear are firstly crystallized in alloy to make grains refine. In progress of solidification, the Al-Sc, Al-Zr-Sc segregation regions are formed in solid solution matrix of Al-Mg alloy owing to the strong interaction of Al atom with Zr, Sc atoms in bulk of alloy, so in the following homogenization treatment, the finer dispersed Al3Sc and Al3 (Sc1-xZrx) second-particles which are coherence with the matrix are precipitated in the segregation region. These finer secondparticles with the strong Al—Zr, Al—Sc covalent bonds can strengthen the covalent bonds in matrix of the alloy, and also enhance the hardness and strength of Al-Mg alloy. Those finer second-particles precipitated in interface of sub-grains can also strengthen the covalence bonds there, and effectively hinder the interface of sub grains from migrating and restrain the sub-grains from growing, and cause better thermal stability of Al-Mg alloy.  相似文献   

12.
1 INTRODUCTIONAddingofminorMn ,Cr ,Ti,B ,Zr ,Sc ,Agintoaluminumalloyscanremarkablychangethemi crostructuresandpropertiesofaluminumalloys[18] .Amongthem ,theeffectofminorScandZrhasre ceivedspecialattention .Onthe 1stInternationalScandiumConferenceheldinMoscowin 1994 ,Rus sianmetallurgistsdescribedtheapplicationprospectofaluminumalloyscontainingScinaerospace ,aviation ,warshipsandnuclearindustry ,whichhasstimulatedmanyindustrialcountries’researchinterestinthiskindofalloys .Atpresent…  相似文献   

13.
采用第一原理赝势平面波法,计算了单独添加微量Sc、Zr及复合添加Sc、Zr后Al-Mg体系的能量与电子结构。结果显示:与纯Al和Al-Mg比较,Al-Sc、A1-Mg-Sc、Al3-Sc、Al-Zr、Al-Mg-Zr、Al3-Zr、Al-Sc-Zr、Al-Mg-Sc—Zr的负合金形成热与结合能增大,表明这些晶胞在Al-Mg合金体系中易形成且结构稳定;对电子态密度进一步分析发现,与单独添加Sc或Zr相比,复合添加Sc、Zr时,晶体在费米能级附近的低能区有更多的成键电子;复合添加Sc和Zr,合金体系结晶凝固时,有更多的晶粒提供非均匀形核作用的场所,因而晶粒细化的效果明显好于单独添加Sc或Zr。  相似文献   

14.
Al-Mg-Sc合金的组织和性能   总被引:1,自引:1,他引:0  
针对飞机战伤抢修和日常维修工作发展的要求,自行研制了具有高的综合力学性能的Al-5Mg-0.3Sc板材,利用金相显微镜、扫描电镜等分析手段研究了Sc对Al-Mg合金组织、性能的影响规律。试验研究表明:添加质量分数为0.3%的Sc的Al-Mg合金铸态组织得到显著细化,枝晶组织在相当程度上得到消除;Al-5Mg-0.3Sc的力学性能和2A12(LY12)的力学性能相当,而Al-5Mg-0.3Sc比2A12有较高的抗海水腐蚀能力;Al-5Mg-0.3Sc板材可以替代2A12板材作为飞机损伤铝合金结构板材的修复材料。  相似文献   

15.
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…  相似文献   

16.
研究了在5A01铝合金基础上添加0.2%Sc和0.3%Sc后合金的显微组织、力学性能、腐蚀性能及焊接性能。结果表明,微量Sc的加入,初生AlSo或灿,(Sc,zr)粒子可成为有效的非均质晶核,大大地细化合金的铸态晶粒,次生Al3Sc或Al3(Sc,Zr)粒子能有效地钉扎位错和亚晶界,稳定亚结构并强烈抑制合金的再结晶。因此,加入Sc后的试验合金基体及焊接强度提高,腐蚀性能和焊接性能与5A01铝合金相当,甚至更好。  相似文献   

17.
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.  相似文献   

18.
微量Sc元素对AZ91镁合金组织性能的影响   总被引:8,自引:1,他引:7  
王斌  易丹青  罗文海  周玲伶  方西亚 《铸造》2005,54(5):459-461
本试验以AZ91镁合金为基,制备了含Sc的AZ91镁合金.研究了微量Sc对AZ91镁合金组织性能的影响.结果表明,Sc的加入,在AZ91中形成了Al3Sc新相;细化了AZ91合金的铸态组织,改变了第二相Mg17Al12的形貌;显著提高了材料的硬度、强度;抑制了材料的动态再结晶,且延缓了材料的时效硬化行为.  相似文献   

19.
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.  相似文献   

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