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1.
Sn对镁合金显微组织和力学性能的影响 总被引:79,自引:10,他引:69
研究了Sn对镁合金显微组织和力学性能的影响。研究结果表明,纯镁中加入Sn后能使纯镁铸锭中粗大的柱状晶转化为均匀的等轴晶,并有效地细化晶粒,同时在显微组织中形成具有立方C1结构的Mg2Sn颗粒相。由于Mg2Sn颗粒相显微硬度和熔点高,热稳定性好,因而对基体具有有效的弥散强化作用,提高了MgSn二元合金的室温及高温强度。在Mg9Al0.8Zn基合金中加入少量的Sn便能有效地提高合金的耐热性,而加入过多的Sn反而会导致合金高温强度下降。 相似文献
2.
复合变质对AlSi7Mg合金组织和性能的影响 总被引:2,自引:1,他引:1
通过在铸造AlSi7Mg合金中加入一种新型复合变质剂,研究其对合金力学性能和组织的影响,并采用透射电子显微镜(TEM)研究合金在时效过程中组织的变化。结果表明:采用此新型变质剂可有效提高铸造AlSi7Mg合金的力学性能。合金经535℃×6h固溶化处理和150℃×6h时效处理后,其σb达到351.7MPa,δ达7.79%。经TEM分析,采用此变质剂处理的铸造AlSi7Mg合金在时效过程中不仅会产生Mg2Si相,而且发现了一种新的时效强化相。通过分析,认为该相的析出过程与Mg2Si相似,且其析出温度要较Mg2Si相略低。由于此新强化相的析出使得合金在较低温度时效时即可获得较好的强化效果,使合金在T5状态下即可获得高的综合力学性能 相似文献
3.
韦绿梅 《中国有色金属学报》1998,(Z1)
研究了双重时效的低温形变热处理(LTHT)对AlMgSiRE合金力学性能的影响。双重时效的低温形变热处理使AlMgSiRE合金获得抗拉强度σb=350MPa,σ0.2=291MPa和延伸率δ=6%的最佳综合力学性能。显然用这种处理工艺比用固溶淬火+时效的普通热处理工艺优越。研究表明,双重时效的低温形变热处理是有效提高REAl合金强度的一种值得推广的工艺。 相似文献
4.
微量Sc和Zr对Al—Mg合金铸态组织的晶粒细化作用 总被引:32,自引:5,他引:32
制备了Al5Mg、Al5Mg0.2Sc、Al5Mg0.1Zr和Al5Mg0.2Sc0.1Zr四种铸态合金,采用金相显微镜和扫描电镜观察分析了微量Sc和Zr对AlMg合金铸态组织的晶粒细化作用及其机理。结果发现,02%的Sc并未使AlMg合金产生晶粒细化作用,而02%的Sc与01%的Zr复合添加则使AlMg合金产生了极其强烈的晶粒细化作用。这一作用的产生,是由于Sc、Zr与Al在合金熔体中生成了Al3Sc和Al3Zr复合粒子,这种粒子在合金凝固过程中,起到了非均质晶核细化晶粒的作用 相似文献
5.
铸造Al—Si—Mg合金的时效特性及形变机制 总被引:1,自引:1,他引:1
研究了AlSiMg系A357合金在不同时效状态下的显微组织、力学性能及形变特性。结果表明,时效条件不同,合金的强塑性配合不同,165℃短时时效,强塑性搭配较好;155℃,4h预时效,再经175℃,12h最终时效,进一步提高合金强度的同时,保证了塑性。不同温度下短时时效,析出物均为GP区,形变以位错切过的方式进行;长时时效,析出物均为β相,形变以位错绕过的方式进行。双级过时效处理,改善了β相的析出形态,使得滑移位错均匀分布 相似文献
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Sc对Al—Li—Cu—Mg—Zr合金组织与性能的影响 总被引:4,自引:0,他引:4
研究了Sc对Al-Li-Cu-Mg-Zr合金的显微组织与拉伸性能的影响,结果表明,δ'(Al3Li)和S'(Al2CuMg)仍为含Sc合金中的主要强化相,Sc细化了合金的晶粒,降低了δ'颗粒的长大速度。促进了S'相的析出和均匀弥散分布,还使合金析出Al3Sc颗粒和Al3Li/Al3Sc复合析出相颗粒,这两种颗粒都有益于合金的性能,因此,加入Sc后合金表现出良好的强塑性配合。 相似文献
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Zn,Al对Mn—Cu减振合金减振性能的影响 总被引:8,自引:2,他引:6
研究了合金元素Zn、Al对新型减振降噪(高阻尼)铸造MnCu合金Ms点、减振性能及力学性能的影响,重点讨论了合金成分与减振性能SDC及力学性能的关系。开发了高阻尼、高强度锰铜基阻尼合金ZMnD1J,最优成分为Mn50%、Zn5%、Al2%、余量Cu。典型性能:SDC=44.5%,σb=678MPa,δ=24.1%。MnCu系新型高阻尼功能材料的减振能力很高,同时力学性能可达ZGD345570的水平,可做结构材料使用。 相似文献
10.
退火工艺对Al-Mg-Sc-Zr合金组织与性能的影响 总被引:3,自引:0,他引:3
研究了退火温度和退火时间对含微量Sc和Zr的Al5Mg合金的显微组织和力学性能的影响。结果表明:该合金在热轧—冷轧后130℃,3h退火处理可获得最佳的力学性能,σ0.2=308MPa,σb=406MPa,δ=15%;退火过程中,由于Al3(Sc,Zr)第二相对位错和亚晶界的钉扎作用,合金中依次发生不同程度的回复和部分再结晶。 相似文献
11.
Effects of Ce and Sb on the microstructure and properties of AZ91D magnesium alloy prepared by the EPC process 总被引:1,自引:0,他引:1
LI Jiqiang DONG Xuanpu FAN Zitian WANG Yuanqing 《稀有金属(英文版)》2008,27(1):41-45
The effects of small amounts of cerium and antimony additions on the microstructure and the mechanical properties of AZ91D(Mg-9Al-Zn) based alloy were researched via the expendable pattern casting(EPC) process.The results show that the microstructure is obviously refined and the tensile strength of the AZ91D based alloy at ambient temperature is significantly improved.When compared to AZ91D,the AZ91D-1.0?-0.4%Sb alloy has higher ultimate tensile strength and elongation.Its ultimate tensile strength and elongation are enhanced by 39% and 47%,respectively.The morphology of the tensile fracture of the AZ91D-1.0?-0.4%Sb alloy has more characteristics of quasi-cleavage.This indicates that it has had a larger plastic deformation before failure.The tensile strength and elongation decrease with the increase of Ce and Sb contents because of the coarsening and volume increase of CeSb and Al11Ce3 phases. 相似文献
12.
研究了锑对AZ91D镁合金微观组织的影响。在AZ91D镁合金熔炼过程中加入三氧化二锑引入锑元素,用光学显微镜对加锑前后合金显微组织及其变化情况进行研究,发现锑的加入可使AZ91D镁合金的组织发生明显变化,β-Mg17Al12脆性相由连续网状分布逐渐变为离散状。同时利用扫描电镜、能谱仪和透射电镜分析了锑在合金中的存在形式。结果表明,锑在AZ91D镁合金中主要以两种形式存在:固溶在α-Mg、β相中;形成新相Mg3Sb2。锑在镁合金中生成的新相Mg3Sb2既作为异质形核核心细化组织,又会聚集在固液界面前沿抑制晶体的长大,从而对镁合金起到细化晶粒的作用。 相似文献
13.
Effect of rare earth additions on microstructure and mechanical properties of AZ91 magnesium alloys 总被引:5,自引:0,他引:5
In order to meet the demands of high temperature components in automobile, the microstructure and mechanical properties of several new die-casting AZ91-rare earth (RE) magnesium alloys were studied. The alloys were characterized by optical microscopy (OM), scan electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), tensile and creep tests. The results show that Ce addition has little effect on the mechanical properties of AZ91 alloy at high temperature, while Y and Nd addition play important role in the improvement of creep resistance. New alloys containing Y or Nd with excellent high temperature performance are selected to produce cylinder head cover of high power diesel engine of Red Flag car and oil pan of Besturn car. The new magnesium alloys with RE addition for die-casting have potential to produce power-train parts, and can greatly decrease weight. 相似文献
14.
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
15.
通过盐雾腐蚀试验,研究了稀土Y对AZ91D镁合金耐腐蚀性能的影响。用光学显微镜(OM)观察组织结构,应用XRD对其进行物相分析,采用静态失重法计算其腐蚀速率,比较含Y和不含Y的AZ91D镁合金的组织和耐腐蚀性能。结果表明,Y+AZ91D镁合金在NaCl溶液中具有优异的耐蚀性,并且随Y含量的增加,Mg17Al12相增多,针状组织Al4MgY也增多,细化了合金的微观组织,耐腐蚀性能也进一步得到提高。 相似文献
16.
喷射成形Mg-9Al-xZn合金的微观组织演变 总被引:1,自引:0,他引:1
利用喷射成形技术制备AZ91、AZ92和AZ93镁合金沉积柱坯,并对其微观组织演变进行观察.结果表明:铸态普通凝固AZ91合金的晶粒粗大,脆性β-Mg17Al12相连续分布成网状结构;而喷射成形AZ91、AZ92和AZ93合金的组织均匀,晶粒被充分细化,β-Mg17Al12相的网状结构被打破;喷射沉积快速凝固条件下高的冷却速率促进了过饱和α-Mg固溶体组织的形成,使得偏析相减少,形态改善;Zn含量的增加降低了Al在Mg中的溶解极限,促进了β-Mg17Al12相在晶界的析出及α-Mg+β-Mg17Al12离异共晶组织的形成;Zn元素的偏析倾向为激活成分过冷区内的形核质点提供了驱动力,从而阻碍了晶粒长大. 相似文献
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18.
Ran XIAO Wen-cai LIU Guo-hua WU Liang ZHANG Bao-liang LIU Wen-jiang DING 《中国有色金属学会会刊》2021,31(6):1572-1586
The microstructure, mechanical properties and flame resistance behavior of the AZ91?1Ce alloys with different Ca additions were firstly investigated. Then, the effect of processing parameters, including applied pressures and rotation speeds, on the microstructure and mechanical properties of the rheo-squeeze casting AZ91?1Ce?2Ca alloy was studied. The results indicate that with the increase of Ca content, the microstructure is refined and the flame resistance of the AZ91?1Ce?xCa alloys increases. But when the Ca content exceeds 1 wt.%, with the Ca content increasing, the mechanical properties of the AZ91?1Ce?xCa alloys reduce rapidly. For rheo-squeeze casting process, the increase of applied pressure and rotation speed can both bring about significant refinement in the microstructure of the AZ91?1Ce?2Ca alloy and reduction of the porosity, so the mechanical properties increase. Compared to conventional casting, the AZ91?1Ce alloy with the addition of 2 wt.% Ca by rheo-squeeze casting not only guarantees the oxidation resistance (801 °C), but also improves mechanical properties. 相似文献
19.
The corrosion behaviours of four kinds of rolled magnesium alloys of AZ31, AZ91, AM60 and ZK60 were studied in 1 mol/L sodium chloride solution. The results of EIS and potentiodynamic polarization show that the corrosion resistance of the four materials is ranked as ZK60>AM60>AZ31>AZ91. The corrosion processes of the four magnesium alloys were also analyzed by SEM and energy dispersive spectroscopy(EDS). The results show that the corrosion patterns of the four alloys are localized corrosion and the galvanic couples formed by the second phase particles and the matrix are the main source of the localized corrosion of magnesium alloys. The corrosion resistance of the different magnesium alloys has direct relationship with the concentration of alloying elements and microstructure of magnesium alloys. The ratio of the β phase in AZ91 is higher than that in AZ31 and the β phase can form micro-galvanic cell with the alloy matrix, as a result, the corrosion resistance of AZ31 will be higher than AZ91. The manganese element in AM60 magnesium alloy can form the second phase particle of AlMnFe, which can reduce the Fe content in magnesium alloy matrix, purifying the microstructure of alloy, as a result, the corrosion resistance of AM60 is improved. However, due to the more noble galvanic couples of AlMnFe and matrix, the microscopic corrosion morphology of AM60 is more localized. The zirconium element in ZK60 magnesium alloy can refine grain, form stable compounds with Fe and Si, and purify the composition of alloy, which results in the good corrosion resistance of ZK60 magnesium alloy. 相似文献