共查询到18条相似文献,搜索用时 125 毫秒
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对电磁搅拌的铝铁合金在半固态温度条件下用INSTRON-5500R实验机进行单向压缩实验,实验结果表明,铝铁合金在半固态温度变形时,随着变形温度的升高,真应力峰值降低;随着应变速率增加,真应力峰值也增加,随后会发生应变-软化现象。应变速率愈小,软化过程愈长,应力下降愈缓慢。变形试样中心和边缘区域的变形情况不同,中心区域固相颗粒的变形程度大于边缘区域。在不同的变形量、变形温度和变形速率下,其内部固-液两相的流动方式和变形机理不同。固相主要集中在试样的心部发生塑性变形,而液相则流向边部,其组织形貌与变形温度、变形量和变形速率都有直接的关系。 相似文献
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压铸铝铁合金的组织与性能 总被引:1,自引:0,他引:1
采用高倍显微组织观察、力学性能测试等手段,讨论了铝铁系合金在压铸条件下的组织、性能,以及压铸过程中存在的问题。表明压铸铝铁合金的抗拉强度σb可达到242.3MPa,伸长率δ可达到2.7%,显微组织中存在尺寸小的短棒状相,而且压铸试棒组织呈圆环带状分布。 相似文献
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钇对过共晶铝铁合金组织形貌的影响 总被引:1,自引:0,他引:1
针对普通熔铸条件下过共晶Al-Fe合金中初生富铁相严重割裂基体、恶化合金性能的问题,采用稀土元素Y对Al-5?合金进行变质处理。实验结果表明:稀土元素Y抑制了初生富铁相在原有形核基底上生长的趋势,促进初生相形核,对其形态、大小和分布均有显著影响;加入0.1%的Y时,初生富铁相由粗大针片状变为较均匀的花朵状;当Y的加入量增加到0.5%时,初生富铁相向细小的团球状转变,分布均匀;继续增加Y的加入量时,开始出现针片状及少量大花朵状的初生富铁相,组织不均匀,且逐渐粗化。 相似文献
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铸造Al-Fe合金中的Al3Fe等金属间化合物,具有高硬度和极好的耐热、耐磨及抗腐蚀性能,且熔炼合金的原材料来源广、成本低,因此,改善Al-Fe合金的铸态组织,使其应用于生产实践,具有深远意义。本文中作者论述了国内外学者对Al-Fe合金凝固特性的研究现状,并对其研究及应用前景进行了展望。 相似文献
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采用离心铸造技术成功地制得了过共晶Al 10 ?梯度材料 ,离心机转速每分钟 140 0转 ,金属模具预热温度 4 50℃ ,浇注温度 10 0 0℃。采用金相及扫描电子显微镜、HV 5型小负荷维氏硬度计及销盘式ML 10 0型磨粒磨损试验机研究了梯度材料组织、硬度及耐磨性的分布规律。结果表明由于初晶Al3Fe密度比Al液密度高 ,在离心力场中初晶Al3Fe向试样外侧移动。Al 10 ?合金梯度材料的组织分布为最外层初晶Al3Fe含量最多、尺寸也最大 ,由外向内 ,初晶Al3Fe的体积分数及尺寸均逐渐减小 ,且呈梯度变化。在内层一定厚度内 ,完全不含初晶Al3Fe。Al 10 ?合金梯度材料的硬度分布为外层硬度较高 ,由外向内硬度逐渐减小 ,呈梯度分布。Al 10 ?合金梯度材料试样的耐磨性试验结果表明 ,试样从外到内磨损厚度增大 ,即该梯度材料的耐磨性由外至内呈梯度下降的变化趋势。 相似文献
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Mn含量对共晶Al-2%Fe合金组织的影响 总被引:3,自引:0,他引:3
研究了含Mn量对共晶Al-2%Fe合金组织的影响。结果表明,在Al-2%Fe合金中加入Mn后,其组织中出现了先析相(FeMn)Al6,且随着Mn量的增加,先析相的数量增加,当Mn量增加到一定程度后,先析相出现发达的分枝。文中还对Mn的影响机理进行了探讨。 相似文献
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The effects of alloying elements, electromagnetic stirring, reheating and semi-solid formation on the microstructure and mechanical properties of Al-Fe alloys prepared by semi-solid formation were studied. It was found that alloying elements and electromagnetic stirring can alter the morphology and growth mode of the iron-rich phase in Al-Fe alloys; and effectively refine the primary Al3Fe phase. In contrast to the microstructure obtained in conventional casting, the Al3Fe phase becomes thin short rod-like instead of thick needle-like; and the dendritic grain structure almost disappears in the semi-solid formation. The Al3Fe phase can be further refined through being dissolved or fused during subsequent reheating. It was also found that the larger extrusion ratio of semi-solid formation causes a greater crushing effect and therefore the Al3Fe phase is more refined and has more uniform distribution. Moreover, Al-Fe alloys prepared by semi-solid formation exhibit excellent mechanical properties at both room and high temperatures. 相似文献
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搅拌摩擦加工铸态铝铁合金的显微组织 总被引:1,自引:0,他引:1
采用普通熔铸法制备含铁3%(质量分数)的铝铁二元合金,研究多道次往复搅拌摩擦加工(Friction stir processing,FSP)对合金显微组织的影响。结果表明:进行1~3道次往复FSP后,各道次加工区组织不均匀;随着加工道次的增加,组织均匀细化程度增大。合金铸态组织由α-Al和粗大针状Al3Fe相组成,经3道次FSP后,搅拌区组织明显细化。原始铸态组织转变为细小等轴的再结晶晶粒,尺寸为2~5μm,并且部分晶粒中出现层错;粗大的Al3Fe针状相被破碎成长度小于1μm的细小粒状,弥散分布在铝基体晶界和晶粒内部,细化的Al3Fe粒子呈现孪晶结构。 相似文献
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LI Hui GUO Jianting TAN Minghui SUN Chao LAI Wanhui WANG Shuhe Institute of Metal Research Academia Sinica Shenyang China Professor Institute of Metal Research Academia Sinica Shenyang China 《金属学报(英文版)》1993,6(1):40-45
The microstructure,tensile properties at 20—950℃ and creep rupture properties at 700-900℃ in a Ni_3Al-Fe based alloy after high temperature deformation have been studied.Theresults show the microstructure of the alloy is composed of γ′-and β-phases.The grain sizeand yield strength of the alloy is stable when the temperature≤600℃,and it is ductile athigh temperature.The creep of the alloy at 700—900℃ is controlled by the climbing of dislo-cations,and the activation energy for creep is 439 KJ/mol with a stress exponent of 4. 相似文献
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Numerical analysis confirms that in some cases the prepeak in the structure factor causes obvious change in the coordination number, but change in the interatomic distance can be neglected for the study of the medium range order(MRO). In order to model the MRO, it is not possible to get enough information based on the pair correlation function; however the quasi-Bragg equation can be employed to characterize the quasi-period of MRO corresponding to the prepeak position. By assuming that the interatomic distance between Fe and Al atoms hardly varies with composition, structural models were constructed based on the B2-type structure units of ordered FeAI alloy. The quasi-periods for different alloys obtained from the model structures are in reasonable agreement with the experimental ones. 相似文献