INFLUENCE OF CERIUM CONTENT ON DAMPING CAPACITIES OF AS-SPRAY DEPOSITED HIGH SILICON ALLOY ZA27

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EFFECT OF ANNEALING ON DAMPING CAPACITIES OF AS-CAST ZA27 ALLOY

1. Introduction Because ZA27 alloy possesses excellent mechanical properties and high damping capacities, it is widely used in industries. ZA27 alloy has good castability and can be easily cast into various castings by permanent mold casting. The solidification of ZA27 alloy in the permanent mold can be considered to be a nonequilibrium process, and thus the supersaturated aluminum-rich ! phase and unstable copper-rich phase may also be found in the solidified ingot. Those nonequilibrium pha…     

喷雾沉积Ce变质高硅ZA27合金组织与性能

研究了０５％Ｃｅ变质前后喷雾沉积高硅ＺＡ２７合金的组织与力学性能。喷雾沉积高硅ＺＡ２７合金的组织由富Ｓｉ相、光滑无特征区、细层片状共析体、粗层片状共析体所组成；加０５％Ｃｅ变质后，组织结构大大细化，主要由富Ａｌ、Ｃｅ亮点状相、富Ｓｉ、Ｃｅ多角形相以及细层片状共析体组成；显微硬度测量结果表明，Ｃｅ变质提高了材料的塑性，从而有利于高硅ＺＡ２７合金的推广应用。     

INFLUENCE OF ZIRCONIUM ON MICROSTRUCTURE AND DAMPING CAPACITY OF ZA27 ALLOY

1.IlltroductionThedampingcapacityofamaterialreferstotheabilitytoconvertmechanicalenergyofvibrationintoheatthatisdissipatedinthematerial.Itisofgreatsignificancetoimproveitbecausethehighdampingmaterialcanattenuateundesirablenoiseandvibrationandremovethemtothesurroundingsll,2].Itiswellknownforsometimethatcertainzincaluminumajloysfallintothecategoryofhigh-dampingalloys(HIDALLOYS)['].TheZA27ajloyhashighas-caststrength,hardness,andwearresistanceaswellasotherfavorablephysicalproperties.Itisalmos…     

DAMPING CAPACITY OF HIGH SILICON ALLOY ZA27 PREPARED BY SPRM DEPOSITION

1.IntroductionInrecentyearscontinuousattemptshavebeenmade,particularlyinareasofalloydesignandadoptionofnovelprocesstechniques,todevelophighperformancematerialsasseriouscompetitorstotraditiona1engineeringalloys.Inparticular,muchattentionhasbeengiventoarapidsolidificationtechnique-spraydeposition.Itiswell-knownthatthisprocesshaJsimprovedthemechanicalpropertie8greatlyThosematerialsofferadvantagesinaPplicationswherehighdampingcapacityhighstrengthandhighstiffnessaxea..primaxyconcern.Highdampingal…     

Ce对Zn-Al合金组织性能的影响

研究了Ｃｅ对ＺｎＡｌ合金（ＺＡ２７、ＺＡ４３）的力学性能、淬火时效特性及耐磨性的影响。结果表明,Ｃｅ能明显细化合金的铸态组织,提高其强度和塑性。当ＺＡ２７和ＺＡ４３中含Ｃｅ量分别为０．１０％和０．１５％时,获得最佳的力学性能。提出了Ｃｅ细化ＺｎＡｌ合金的机理,加Ｃｅ后成分过冷效应所引起的枝晶熔断脱落对细化α相起主要作用。     

CREEP PROPERTIES OF HIGH SILICON ALLOY ZA27 PREPARED BY SPRAY DEPOSITION

ＣＲＥＥＰＰＲＯＰＥＲＴＩＥＳＯＦＨＩＧＨＳＩＬＩＣＯＮＡＬＬＯＹＺＡ２７ＰＲＥＰＡＲＥＤＢＹＳＰＲＡＹＤＥＰＯＳＩＴＩＯＮ￥ＹＡＮＧＬｉｕｓｈｕａｎ;ＬＩＵＹｏｎｇｃｈａｎｇ;ＹＡＮＧＧｅｎｃａｎｇ;ＺＨＯＵＹａｏｈｅ（ＳｔａｔｅＫｅｙＬａｂｏｒａ...     

Effect of rare earths on phase transformation in as-cast ZA27 alloy dur-ing compressive creep

The effect of the mixed rare earths of Ce on the phase transformation in as cast ZA27 alloy during compressive creep was investigated under 37 MPa and at 160℃ by X-ray diffraction technique and SEM. The results showed that the as cast microstructure of ZA27-RE alloy consisted of a dendritic Al-rich a' surrounded by Zn-rich β' phase, interdendritic ε phase and Zn-rich η phase together with a complex Z phase which was a complex constitute compound, (RE,Cu)Al5Zn16, dispersed in crystal interfaces or branch crystal interfaces and stable during compressive creep test at 160'C. The phase transformations of ZA27-RE alloy, decomposition of β' phase and four transformation, were delayed by the addition of rare earths, also the lamellar structure and the spheroidized structure in ZA27-RE alloy were finer than in ZA27 alloy during compressive creep test at 160℃ at the same creep time, and the compressive creep resistance of ZA27-RE alloy was higher than that of ZA27 alloy.     

MICROSTRUCTURE ANALYSIS AND MECHANICAL PROPERTIES OF Zn—Al ALLOY ROD PRODUCED BY HEATED MOLD CONTINUOUS CASTING

The new technology of continuous casting by heated mold was used to produce directional solidification ZA alloy lines to eliminate the inter defects of these lines and increase their mechanical properties. The results are as follows: (1) The microstruc-ture of the ZA alloy lines is the parallel directional dendritic columnar crystal. Every dendritic crystal of eutectic alloy ZA5 was composed of many layer eutectic β and η phases. The micro structure of hypereutectic ZA alloys is primary dendritic crystal and interdendritic eutectic structure. The primary phase of ZA8 and ZA12 is β, among them, but the primary phase of ZA22 and ZA27 is a. (2) Through the test to the as-cast ZA alloy lines made in continuous casting by heated mold, it is found that the tensile strength and hardness increase greatly, but the elongation decreases. With the increase of aluminum amount from ZA 5 to ZA 12, ZA22 and ZA27, the tensile strength increases gradually. ZA27 has the best comprehensive mechanical properties in these     

稀土对ZA27合金阻尼性能的影响

研究了稀土对ZA27合金阻尼性能的影响规律。结果表明：稀土变质可提高ZA27合金的阻尼性能，经稀土变质后的试样，其内耗是未变质的试样的1．4倍。ZA27合金为发挥其阻尼作用，在频率高于70Hz时，效果明显，且经稀土变质后的试样强迫振动衰减效果比未变质的试样强。     

Effects of solidification and melt treatment on microstructure and mechanical properties of cast ZA27 alloy

1　ＩＮＴＲＯＤＵＣＴＩＯＮＺｉｎｃ ａｌｕｍｉｎｕｍａｌｌｏｙＺＡ2 7ｈａｓｔｈｅｂｅｓｔｃｏｍｂｉｎｅｄｐｒｏｐｅｒｔｉｅｓ,ｅｓｐｅｃｉａｌｌｙｗｅａｒｒｅｓｉｓｔａｎｃｅ ,ａｍｏｎｇｚｉｎｃｂａｓｅｄａｌｌｏｙｓｃｏｎｔａｉｎｉｎｇａｈｉｇｈｃｏｎｔｅｎｔｏｆａｌｕ ｍｉｎｕｍ[1] .Ｗｉｄｅｒａｎｇｅｓｏｆａｐｐｌｉｃａｔｉｏｎｓｈａｖｅｂｅｅｎｆｏｕｎｄｆｏｒｔｈｉｓａｌｌｏｙ ,ａｎｄｆｏｒｂｅａｒｉｎｇｍａｔｅｒｉａｌｓｉｔｒｅ ｐｌａｃｅｓｔｉｎａｎｄａｌｕｍｉｎｕｍｂｒｏｎｚｅ .Ｉｎｏ…     

锰元素对锌基硅相复合材料性能的影响

研究了在硅相球化的ZA27、ZA35及ZA45合金中加入不同量的Mn时，对ZA合金硬度及耐磨性的变化规律。结果表明：在ZA27合金中Mn的加入量对其综合性能影响不大；在ZA35合金中锰的加入量为0.5％时。材料的综合性能较好；在ZA45合金中Mn的加入量≤1.0％时，其综合性能比较好。     

AlP变质Si合金化ZA84合金的组织及力学性能

借助光学显微镜和JEM-2000FX透射电子显微镜(配备OXFORD ISIS EDXS附件)等分析手段,研究了AlP变质Si合金化ZA84合金的组织及力学性能。结果表明,ZA84合金、Si合金化ZA84(S1)合金及AlP变质Si合金化ZA84(P01)合金经固溶处理后,其Mg2Si及τ相的尖锐棱角变钝。ZA84合金的峰值时效时间在2 h,其纳米级的析出相沿基体α-Mg的(0001)密排面的[1010]晶向析出,而S1及P01合金的峰值时效时间推迟至8 h左右,其纳米级的析出相无取向分布。合金的析出机制均为连续析出。ZA84合金通过Si合金化、AlP对组织的变质和细化以及合金热处理,其力学性能得到了显著提高。     

Effect of specific pressure on microstructure and mechanical properties of squeeze casting ZA27 alloy

The effect of specific pressure on the microstructure and mechanical properties of ZA27 squeezed castings with high height-to-thickness ratio was studied. The results of DTA and SEM show that at high specific pressure the eutectic reaction of squeeze casting ZA27 alloy is restrained, and the final solidified structure is (η+ε) phases instead of eutectic phase (β+η+ε). At the same time, the primary reaction is promoted in squeeze casting ZA27 alloy solidified at high pressure, and the fine microstructure is obtained with the increase of pressure. Al and Cu elements are homogeneously distributed in matrix of squeeze casting ZA27 alloy. The homogenously distributed high-density fine ε phase can effectively hinder dislocation motion, and then the strength and plasticity of squeeze casting ZA27 alloy are increased.     

La对ZA27合金组织,机械性能及摩擦磨损特性的影响

研究了Ｌａ对ＺＡ２７合金组织、常温机械性能的影响，并测定了ＺＡ２７（Ｌａ）合金的摩擦磨损特性。结果表明：Ｌａ可以细化合金初生ａ′相，改善共晶相的形貌与分布，提高合金的塑性和韧性指标；ＺＡ２７（Ｌａ）合金的摩擦磨损特性优于ＺＱＳｎ６－６－３     

Ca对ZA63合金组织和力学性能的影响

通过合金制备、微观分析和力学性能测试等方法研究了Ca对ZA63合金微观组织和力学性能的影响.结果表明,当加入Ca元素后,舍金晶粒细化,半连续网状的τ相变为细小粒状或棒状,颗粒状τ相更为细小,并形成了细小高熔点Al_2Ca相.随着Ca含量的增加,固溶时效态合金在室温、150℃和175℃温度下的抗拉强度和延伸率基本上呈先升高后降低的趋势.当Ca含量为1.0%时,合金在各温度下的抗拉强度和延伸率都达到最大值.     

Si含量对Mg-8Zn-4Al-0.3Mn镁合金时效过程的影响

采用光学显微镜、扫描电镜(附EDAX能量分散光谱系统)和差示扫描量热仪(DSC)等分析手段研究了不同Si含量(0～1.61wt%)对Mg-8Zn-4Al-0.3Mn(ZA84)合金时效过程的影响。结果表明,合金经固溶处理后显微硬度较铸态下提高了8%左右,其Mg2Si、τ(Mg32(Al,Zn)49)等相基本未溶入基体中。随着ZA84合金中加入Si量的增加,合金的析出相形成激活能呈增加趋势,峰值时效时间由ZA84合金的2h左右推迟至8h左右,析出相粗化时间较ZA84合金推迟4h以上。合金中加入不同含量Si后其峰值时效显微硬度提高幅度为4%～12%。     

退火温度对Fe-Cr-Mo合金减振性能及力学性能的影响

采用弯曲共振法测量Fe-Cr-Mo合金的减振性能,通过光学显微镜和扫描电镜对合金组织进行观察,研究了退火温度（900～1100℃）对Fe-Cr-Mo合金减振性能和力学性能的影响。结果表明,Fe-Cr-Mo合金在900～1100℃退火温度范围内,随着退火温度的升高,合金的内耗先升高后降低,在1000℃达到峰值4. 7×10^-3。同时,退火温度对合金的力学性能有明显的影响。900℃退火后,合金的抗拉强度和塑韧性最好,抗拉强度为513 MPa,伸长率为37. 25%,断面收缩率为83%,冲击吸收能量为414 J。1100℃退火后,规定塑性延伸强度最大,为395. 5 MPa。      

铝含量对高铝锌基合金性能的影响

研究了Al≥27％的四种高Al锌基合金的组织和性能。由XRD衍射表明：高Al锌基合金的组织由α相、η相及ε相组成,随Al含量的提高,α相、η相细化,其中ZA40合金的抗拉强度及硬度最高,摩擦力矩、摩擦系数最小,在载荷800N和1100N下其耐磨性比ZA27分别提高了36．5％和69．2％。     

轧制变形量对Mg-Zn-Y合金组织和性能的影响

使用光学显微镜、动态机械热分析仪、X射线衍射仪和扫描电镜研究了不同轧制变形量对Mg-4Zn-2Y和Mg-4Zn-4Y合金显微组织、力学性能及阻尼性能的影响。结果表明,经轧制后合金中出现片层状的LPSO相;两种合金阻尼性能中与应变振幅无关的阻尼性能Q^-1₀随着轧制变形量的增加,其变化趋势基本一致,与应变振幅相关的阻尼性能Q^-1_h随着轧制变形量的增加而降低,Mg-4Zn-2Y合金以及Mg-4Zn-4Y合金的阻尼机制为位错型阻尼;随着轧制变形量的增加,合金断口中的韧窝数量增加,解理面减少,主要断裂方式由脆性断裂转变为韧性断裂;相同轧制变形量下,Mg-4Zn-4Y合金的强度优于Mg-4Zn-2Y合金,而阻尼性能要低于Mg-4Zn-2Y合金。