复合变质剂对Al－Si－Cu合金变质效果的研究

借助扫描、电子探针等手段，对Ａｌ－Ｓｉ－Ｃｕ亚共晶铸造合金，加入Ｋ２ＴｉＦ６＋ＮａＢＦ４＋ＮａＦ＋ＮａＣｌ变质剂的变质效果进行了研究。实验结果表明，合金中加入该变质剂，不仅获得完全的变质组织，而且变质效果稳定。     

复合变质剂对Al—Si—Cu合金质效果的研究

借助扫描，电子探针等手段，对Ａｌ－Ｓｉ－Ｃｕ亚共晶铸造合金，加入Ｋ２ＴｉＦ６＋ＮａＢＦ４＋ＮａＦ＋ＮａＣｌ变质剂的变质效果进行了研究。实验结果表明，合金中加入该变质剂，不仅获得完全的变质组织，而且变质效果稳定。     

Al－Si－Cu合金加入Sr复合变质剂的变质效果

用Ｓｒ、Ｎａ、Ｔｉ、Ｂ复合变质剂对Ａｌ－Ｓｉ－Ｃｕ亚共晶铸造合金进行变质处理，其作用与单独加Ｓｒ变质相比，能更好地细化共晶和晶粒，并具有良好的长效性。     

Al—Si—Cu合金加入Sr复合变质剂的变质效果

用Ｓｒ，Ｎａ，Ｔｉ，Ｂ复合变质剂对Ａｌ－Ｓｉ－Ｃｕ亚共晶铸造合金进行变质处理，其作用与单独加Ｓｒ变质相比，能更好地细化共晶和晶粒，并具有良好的长效性。     

熔铸法生产的磷变质剂对过共晶铝－硅合金组织和性能的影响

研究了熔铸法生产的磷变质剂对过共晶Ａｌ－Ｓｉ合金组织和性能的影响，并与传统的Ｃｕ－Ｐ合金变质剂进行了对比。结果表明，熔铸法制备的Ａｌ－Ｃｕ－Ｐ变质剂细化晶粒和提高机械性能的作用远优于Ｃｕ－Ｐ合金。     

熔铸法生产的磷变质剂对过共晶铝—硅合金组织和性能的影响

研究了熔铸法生产的磷变质剂对过共晶Ａｌ－Ｓｉ合金组织和性能和影响，并与传统的Ｃｕ－Ｐ合金变质剂进行了对比。结果表明，熔铸法制备的Ａｌ－Ｃｕ－Ｐ变质剂细化晶粒和提高机构性能的作用远优于Ｃｕ－Ｐ合金。     

一种铜基电阻焊电极合金

报道了一种新的无Ｃｏ，低Ｂｅ电阻焊电极合金Ｃｕ－Ｎｉ－Ｚｒ－Ｂｅ－Ｔｉ（Ｂ合金）。将其组织性能同常用的Ｃｕ－Ｃｏ－Ｂｅ（Ａ合金）电极合金作了对比分析。结果表明，Ｂ俣金硬度，软化度同Ａ合金相近，但导电、导热性明显高于Ａ合金 。     

微量元素对Cu—Ni—Zn—Mn弹性合金性能的影响

研究了微量元素对Ｃｕ－１５Ｎｉ－１３Ｍｎ－２８Ｚｎ弹性合金性能的影响。结果表明：添加（１）０．１８７Ａ１＋０．０１３Ｃｅ＋０．２４Ｆｅ＋０．１Ｂ＋０．１Ｔｉ＋０．１Ｚｒ或（２）０．５Ｔｉ（％质量）的微量元素,可提高合金冷变形态和微双相态的抗拉强度、屈服强度,改善微双相态合金的疲劳性能,缩短微双相化的时间,是适于用作高导电、高耐蚀、抗疲劳器件的弹性材料．     

Al─Ti─C─B中间合金细化剂的研究

研究了新近开发的Ａｌ－Ｔｉ－Ｃ－Ｂ中间合金细化剂，检查了其显微组织及细化工业纯铝及含Ｚｒ铝合金的性能，并与Ａｌ－Ｔｉ－Ｂ中间合金细化剂进行了对比。结果表明：Ａｌ－Ｔｉ－Ｃ－Ｂ中间合金细化剂含有Ａｌ３Ｔｉ、ＴｉＢ２和ＴｉＣ三种第二相，它们形成尺寸细小弥散分布的多相粒子团，其细化工业纯铝晶粒的能力明显优于Ａｌ－Ｔｉ－Ｂ中间合金细化剂，并克服了Ａｌ－Ｔｉ－Ｂ中间合金细化剂易被Ｚｒ原子毒化的弱点。分析认为，Ａｌ－Ｔｉ－Ｃ－Ｂ中间合金优异的细化性能归功于多相粒子团表面凹陷处的物理化学作用     

Al—Ti—C—B中间合金细化剂的研究

研究了新近开发的Ａｌ－Ｔｉ－Ｃ－Ｂ中间合金细化剂，检查了其显微组织及细化工业纯铝及含Ｚｒ铝合金的性能，并与Ａｌ－Ｔｉ－Ｂ中间合金细化剂进行了对比。结果表明，Ａｌ－Ｔｉ－Ｃ－Ｂ中间合金细化剂含有Ａｌ３Ｔｉ、ＴｉＢ２和ＴｉＣ三种第二相，经小弥散分布的多相粒子团，其细化工业纯铝晶粒的能力明显优于Ａｌ－Ｔｉ－Ｂ中间合金细化剂，并克服了Ａｌ－Ｔｉ－Ｂ中间合金细化易被Ｚｒ原子毒化的弱点，分析认为Ａｌ－Ｔｉ－Ｂ     

Ti对ZA35合金组织及电化学腐蚀行为的影响

利用X射线衍射和金相显微镜等手段,研究了不同Ti含量的ZA35合金组织,采用动电位扫描方法测定合金的极化曲线,探讨了Ti对ZA35合金的电化学腐蚀行为的影响规律。结果表明,在3.5%的NaCl溶液中,与ZA35合金相比,添加0.1%的Ti的ZA35合金的腐蚀电流密度减小了56.2%。添加0.1%的Ti可使ZA35合金晶粒和枝晶细化,在NaCl溶液中电化学腐蚀时,腐蚀产物阻塞了细小晶界,提高了合金耐电化学腐蚀性能。     

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.     

Effects of minor Sr,Sn and Sc addition on as-cast microstructure and mechanical properties of ZA84 magnesium alloy

The effects of minor Sr, Sn and Sc addition on the as-cast microstructure and mechanical properties of the ZA84 magnesium alloy were compared. The results indicate that addition of 0.1%Sr, 0.5%Sn or 0.3%Sc (mass fraction) to the ZA84 alloy can refine the grains of the alloy. Furthermore, addition of 0.1%Sr to the ZA84 alloy does not obviously change the morphology and distribution of Mg32(Al,Zn)49 phase. However, addition of 0.5%Sn or 0.3%Sc not only refines and modifies the Mg32(Al,Zn)49 phase but also suppresses the formation of Mg32(Al,Zn)49 phase, especially with the addition of 0.3%Sc. Furthermore, addition of 0.1%Sr, 0.5%Sn or 0.3%Sc to the ZA84 alloy improves the tensile properties at room temperature and 150℃, especially with the addition of 0.1%Sr and 0.3%Sc. However, addition of 0.1%Sr is not beneficial to the creep properties, and addition of 0.5%Sn has no obvious influence on the creep properties. Oppositely, addition of 0.3%Sc to the ZA84 alloy greatly improves the creep properties.     

Effect of Mg-based spherical quasicrystal on microstructures and mechanical properties of ZA54 alloy

To improve the strength,toughness and heat-resistance of magnesium alloy,the microstructure and mechanical properties of ZA54 alloy reinforced by icosahedral quasicrystal phase(I-phase) particles were studied.Exceptα-Mg,φ-phase andτ-phase,MgZnYMn I-phase particles can be obtained in ZA54-based composites by the addition of icosahedral quasicrystal-contained Mg-Zn-Y-Mn master alloy.The introduction of MgZnYMn I-phase into ZA54 alloy has great contribution to the refinement of matrix microstructures and the improvement of mechanical properties.When the addition of Mg-based spherical quasicrystal master alloy is up to 3.5%(mass fraction) ,the macro-hardness of ZA54-based composites is increased to HB 68.The impact toughness of composites reaches the peak value of 18.3 J/cm2,which is about 29%higher than that of ZA54 mother alloy.The highest tensile properties at ambient and elevated temperatures with master alloy addition of 2.5%(473 K) are also obtained in ZA54-based composites with 3.5%(mass fraction) Mg-Zn-Y-Mn master alloy addition.The ultimate tensile strength of composites at ambient and elevated temperatures are 192.5 MPa and 174 MPa,which are 23.4%and 33.8%higher than that of ZA54 mother alloy,respectively. The improved mechanical properties are mainly attributed to the pinning effect of I-phase on grain boundaries.     

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     

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.     

Effects of Ti on the Brazability of Zn-22Al-xTi Filler Metals as Well as Properties of Cu/Al Brazing Joints

设计并采用Zn-Al-Ti系列钎料对Cu和Al异种金属实施了钎焊,并对Zn-22Al-xTi/Cu界面处的相组成和金属间化合物形貌进行了分析。结果表明：在Zn-22Al中添加0.01%至0.05%的Ti可以显著细化钎料组织,而且Zn-22Al-0.03Ti在Cu基板上的铺展面积比Zn-22Al高出60.4%,但Ti的添加会提高Zn-22Al钎料的熔点和熔化区间。另外,在钎料中添加微量的Ti可以优化Cu/Al接头中Cu侧界面化合物的组织并减小其厚度。相比Zn-22Al钎料,Zn-22Al-0.03Ti钎焊所得Cu/Al接头强度要高出13.4%,而且接头断裂位置由化合物层转移至钎料内部。X射线衍射结果显示,钎焊过程中有CuAl2,Cu9Al4,CuZn 3种化合物产生于钎料与Cu基板界面处     

变质剂对ZA27合金半固态等温热处理组织的影响

研究了变质剂Ti、B－Ti及Zr对ZA27合金铸态组织和半固态等温热处理组织的影响。结果表明：Zr的变质效果最好,下来依次是B－Ti,Ti经半固态等温热处理后都可获得触变成形所需的半固态非枝晶组织、但变质组织越细,越易获得良好的非枝晶组织,变质效果越差,需要热处理的时间越长或温度越高。     

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

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均匀化处理对ZA35-0.3Zr合金组织及性能的影响

为了探索均匀化处理对ZA35-0.3Zr合金组织和性能的影响规律,通过组织分析、力学性能、电化学性能测试,确定了ZA35-0.3Zr合金均匀化处理的适宜温度和时间。结果表明,ZA35-0.3Zr合金枝晶偏析明显,晶界上Cu富集严重,存在非平衡β相。随着均匀化处理时间增加,ZA35-0.3Zr合金中CuZn5相逐渐消除,β相共析分解程度加大。对合金进行370℃×12h均匀化处理后,晶界处CuZn5相消除,枝晶偏析大大减少,同时非平衡β相基本消除,抗拉强度为306MPa,伸长率为7.35%。在3.5%的NaCl溶液中,开路电位与未均匀化处理合金相比变正,腐蚀电流密度减小了33.1%,耐腐蚀性增强。ZA35-0.3Zr合金适宜的均匀化处理工艺为370℃×12h。