共查询到19条相似文献,搜索用时 234 毫秒
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目的 研究稀土Y对热浸镀铝层的影响,提高热浸镀铝件的耐蚀性能.方法 通过向热浸镀铝液中添加不同量的铝钇合金,获得稀土Y含量不同的热浸镀铝件.选用3.5%的NaCl溶液为腐蚀溶液,利用SEM、EDS观测其形貌、成分,并使用电化学测试和全浸试验研究稀土Y对镀层耐蚀性能的影响.结果 当添加0.2%Y时,热浸镀铝层表面平整、无孔洞,针状相细小,镀铝层减薄,过渡层由锯齿状转变为连续带状.稀土Y的添加使镀铝件的自腐蚀电位正移,自腐蚀电流密度减小,添加量为0.2%时,自腐蚀电位最正,为?0.7857 V,自腐蚀电流密度最小,为1.3505×10?8 A/cm2.与添加其他稀土元素相比,添加0.2%Y时,镀层的破裂电位Eb最正,为?0.6957 V.不同稀土含量的热浸镀铝件的交流阻抗谱都为单一的容抗弧,当稀土Y添加量为0.2%时,容抗弧半径最大.全浸试验中,添加0.2%Y的镀件的腐蚀速率最低.结论 稀土Y的添加可以使热浸铝层光滑、连续,且具有提高其耐腐蚀性的作用.Y添加量为0.2%时,镀铝件的耐蚀性最好. 相似文献
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研究了合金元素Cd含量对AM50-Y-0.6Sb镁合金的显微组织和腐蚀性能的影响.研究表明,AM50-Y-0.6Sb合金组织主要由α-Mg固溶体、β-Mg17 Al12相、Al2Y相、YSb相组成.随着Cd含量增加,合金组织逐渐细化,Cd固溶于基体不形成新相,当Cd含量为1%时,晶粒和析出相最为均匀细小分布.合金腐蚀速率和腐蚀电流密度随着Cd的增加而降低,而自腐蚀电位正移.当Cd含量为1%时,合金耐蚀性最佳,腐蚀速率仅有1.07 mg·cm-2·d-1,比未添加Cd合金降低了42.5%. 相似文献
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稀土钇对AZ80镁合金微观组织和性能的影响 总被引:1,自引:0,他引:1
采用扫描电镜(SEM),金相显微镜(OM),X射线衍射(XRD),拉伸试验及腐蚀失重等测试手段对添加不同含量稀土钇对AZ80镁合金微观组织和性能的影响进行了研究。结果表明,适量钇的添加使得AZ80镁合金的组织得到细化,β-Mg17 Al12相的数量显著下降,并且由连续网状分布变为断续、均匀分布,同时生成新的稀土相Al2Y。添加0.5%Y时,合金室温下抗拉强度达到199.286 MPa,伸长率为6.155%,分别增加了7.49%,7.98%,腐蚀速率为0.2585 mg.cm-2.d-1,仅为原始合金的48.07%,表现较好的综合性能。 相似文献
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钇对AM60B镁合金显微组织和性能的影响 总被引:4,自引:0,他引:4
采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、电子万能实验机及电化学工作站,研究了Y对AM60B镁合金显微组织、常温及高温(175℃)力学性能和耐蚀性能的影响。结果表明:AM60B中加入Y后,形成了新的热稳定Al2Y相,沿着Mg177Al12相分布,使得Mg17Al12相由网状分布向颗粒状改变。Y加入量为0.6%时,合金试样力学性能和耐蚀性能都有所提高,当Y的加入量达到1.2%时,合金的XRD曲线出现了较强的Al2Y相衍射峰,在175℃时合金抗拉强度达到最高(为147MPa),室温力学性能也达到最佳,并且合金的腐蚀电位明显正移达到一1.02V。Y的添加量从1.2%增加到1.8%时,合金的腐蚀电位变化不大,力学性能也有所下降。 相似文献
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添加稀土Er于熔剂中对铸态AZ91镁合金组织与性能的影响 总被引:3,自引:0,他引:3
研究了熔炼时在熔剂(42%MnCl2 53%LiCl 5?F2,质量分数,%)中添加稀土Er对铸态AZ91镁合金显微组织、力学性能、断口形貌以及腐蚀行为的影响。结果表明:在熔剂中添加稀土Er能够去除镁合金熔炼过程中产生的熔剂夹杂,净化镁合金熔体,提高铸态AZ91镁合金的拉伸性能和耐腐蚀性能;当熔剂中添加10%的稀土Er时,镁合金的抗拉强度σb和伸长率δ分别从156MPa和1.8%上升到最大值220MPa和4.1%;同时,镁合金在5%NaCl水溶液中的腐蚀速率从1.20mg/(cm2.d)下降到最小值0.15mg/(cm2.d);然而,随着稀土Er在熔剂中添加量的进一步提高,合金中开始有φ-(Al7ErMn5)和τ-(Al66.7Mg23.3Er10)等含有稀土Er的相生成,消耗了合金中的Al和Mn元素,改变了β-(Mg17Al12)相的形态;而且沿枝晶界附近分布的粗大φ-(Al7ErMn5)相降低了枝晶之间的结合力,使得合金的σb和δ下降;同时,部分网状的β-(Mg17Al12)相断裂,呈离散的块状,导致合金的腐蚀速率增加;熔剂中添加稀土Er不改变镁合金的断裂机理,断裂机制仍为准解理断裂。 相似文献
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研究了添加0.1 mass%稀土Y和经过粉末渗铝处理的铸造K38高温合金900℃浸盐(盐的成分为75%Na2SO4+25% K2SO4)热腐蚀行为.结果表明,稀土Y改性和渗铝处理均提高了合金的耐蚀性.含Y合金促进了Al的选择性氧化;渗铝合金表面生成了一层连续的Al2O3膜,该膜层抑制了内氧化及内硫化的发生,显著提高了合金的耐蚀性能. 相似文献
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Feng Wang Jibao Li Jing Liu Dan Lv Pingli Mao Zheng Liu 《金属学报(英文版)》2014,27(4):609-614
The influences of Ca and Y additions on the microstructure and corrosion resistance of vacuum die-cast AZ91 alloys were investigated by optical microscope,electron scanning microscope,weight-loss test,and electrochemical corrosion experiment.The results indicate that the Ca or Ca and Y additions refined the microstructure and decreased the amount of Mg17Al12 phase on grain boundaries in the alloys.Meanwhile,the addition of Ca and Y led to the formation of network Al2 Ca phase and rod-like Al2 Y phase,improved the corrosion resistance of AZ91 magnesium alloy.Compared with AZ91 alloy,the corrosion rate of AZ91–1.5Ca–1.0Y alloy was decreased to 16.2%,and its corrosion current density was dropped by one order of magnitude after immersion in 3.5 wt% NaCl solution for 24 h. 相似文献
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Z.H. Huang X.F. Guo Z.M. Zhang C.J. XuSchool of Materials Science Engineering Xi''''an University of Technology Xi''''an China 《金属学报(英文版)》2005,18(2):129-136
1. IntroductionM agnesium alloysare w idely used in autom otive, com m unicated, electronic and aerialindustriesand predicted to be one ofthe m ostim portantlow -density and high-strength m aterialsin the 21th centu-ry ow ing to theirlow density,high spec… 相似文献
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AZ80 magnesium alloys were deformed at 200,250,300,350 and 400℃ with different deformation degree of 50%,75%, 83%,87%and 90%,respectively.The corrosion properties of different deformed AZ80 samples were studied by galvanic test in 3.5%NaCl solution.The results show that plastic deformation could improve the corrosion resistance of AZ80 alloy;and the corrosion rate of AZ80 deformed at 250℃ with the deformation degree of 83%was the lowest,which was 33%of the as-cast AZ80 alloy.Further studies of the microstructure show that the refined grain size and continuously distribution ofβphase around the grain boundary did have a positive effect on the improvement of corrosion resistance of AZ80 alloys.For AZ80 alloys,the smaller the grain size is,the more homogeneous the structure is,and the better the corrosion resistance is. 相似文献
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采用电化学、静态失重、盐雾腐蚀法研究了Mn对热处理态AZ91合金耐蚀性能的影响,利用扫描电镜观察试样的微观形貌,用X射线衍射仪分析合金的物相组成和腐蚀产物。结果表明,Mn与AZ91合金中的Al形成了独立相Al6Mn,该相溶解到Mg固溶体中提高了Mg的电极电位,进而提高了合金的耐腐蚀性;Mn加入后使合金的自腐蚀电位升高,自腐蚀电流密度降低,降低了合金的腐蚀速率,进而提高了合金的耐腐蚀性能,且三种实验方法都表明AZ91-0.8Mn合金的耐腐蚀性能最好。 相似文献
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The influence of relative humidity (80–90–98% RH) and temperature (25 and 50 °C) on the corrosion behaviour of AZ31, AZ80 and AZ91D magnesium alloys was evaluated using gravimetric measurements. The results were compared with the data obtained for the same alloys immersed in Madrid tap water. The corrosion rates of AZ alloys increased with the RH and temperature and were influenced by the aluminium content and alloy microstructure for RH values above 90%. The initiation of corrosion was localised around the Al–Mn inclusions in the AZ31 alloy and at the centre of the α‐Mg phase in the AZ80 and AZ91D alloys. The β‐Mg17Al12 phase acted as a barrier against corrosion. 相似文献
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The effects of yttrium addition on microstructure and mechanical properties of as-extruded AZ31 magnesium alloys were investigated by OM,XRD and SEM.The results show that the addition of yttrium results in the formation of a new phase,Al_2Y. When the addition of yttrium is higher than 1.48%-2.91%(mass fraction),another new phase,Al_3Y_5Mn_7,forms,and the amount ofβ-Mg_(17)Al_(12) phase in the AZ31 alloy decreases sharply.The tensile test at room temperature indicates that the yield strength of as-extrude... 相似文献
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Two types of AZ91 magnesium alloys containing rare earth element Ce or La were fabricated. Hydrogen evolution and electrochemical tests were carried out to evaluate the corrosion behavior of new AZRE (RE = Ce or La) and AZ91 alloys in 3.5% NaCl solutions (pH 6.50). Various corrosion rate tests indicated that addition of RE obviously enhanced corrosion resistance of AZ91 magnesium alloy. The optimal content of RE was 0.92% for Ce and 0.66% for La. Scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and low‐angle X‐ray diffraction (XRD) were used to characterize the effect of RE addition on microstructure and corrosion product film of AZ91 magnesium alloy. The refined β phase and formation of γ phase in AZRE alloy were observed by SEM, which resulted in the improvement of corrosion resistance due to the depression of microgalvanic couples. Moreover, the enhanced protective effectiveness of corrosion products was another reason for the improved corrosion resistance. 相似文献
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Shou-Ren Wang Pei-Quan Guo Li-Ying Yang Yanjun Wang 《Journal of Materials Engineering and Performance》2009,18(2):137-144
Effects of yttrium (Y) on the microstructure and properties of as-cast Mg-Al-Zn (AZ91) alloys were studied. Y additions not
only change the microstructure but also influence the mechanical properties of AZ91 alloy. AZ91 unmodified alloys under as-cast
state indicate that eutectic phase Mg17Al12 is continuous and reticulated. Yttrium addition to AZ91 casting alloys has an important influence on the primary-phase and
precipitation. When the Y content is 0.3 wt.%, no Y-containing compound was observed. When the Y content is 0.6 and 0.9 wt.%,
Al2Y phase formed in the alloy and the growth morphology of eutectic Mg17Al12 phase is modified. When the Y content is further increased to 1.2 wt.%, the Al2Y phase becomes coarser and Mg17Al12 transforms into a cotton-shape structure. The results showed that Y can improve significantly as-cast microstructure of AZ91
alloys, refining Mg17Al12 phase and increasing in hardness and strength and decreasing in impact toughness and elongation. 相似文献
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《中国有色金属学会会刊》2022,32(8):2510-2526
The effects of yttrium (Y) and yttrium + calcium (Y+Ca) additions on the electrochemical properties and discharge performance of the as-extruded Mg?8Al?0.5Zn?0.2Mn (AZ80) anodes for Mg?air batteries were investigated. The results show that the addition of 0.2 wt.% Y increased the corrosion resistance and discharge activity of AZ80 anode. This was attributed to the fine and spherical β-Mg17Al12 phases dispersing evenly in AZ80+0.2Y alloy, which suppressed the localized corrosion and severe “chunk effect”, and facilitated the rapid activation of α-Mg. Combinative addition of 0.2 wt.% Y and 0.15 wt.% Ca generated grain refinement and a reduction of the β-Mg17Al12 phase, resulting in a further enhancement in discharge voltage. However, the incorporation of Ca in Mg17Al12 and Al2Y compounds compromised the corrosion resistance and anodic efficiency of AZ80+0.2Y+0.15Ca anode. Consequently, AZ80+0.2Y anode exhibited excellent overall discharge performance, with the peak discharge capacity and anodic efficiency of 1525 mA·h·g?1 and 67% at 80 mA/cm2, 13% and 14% higher than those of AZ80 anode, respectively. 相似文献