CALCULATION OF ELECTROCHEMICAL OVERPOTENTIAL AND CONCENTRATION OVERPOTENTIAL BASED ON CURVE OF ANODIC POLARIZATION IN HYDROGEN STORAGE ALLOY ELECTRODE

１ＩＮＴＲＯＤＵＣＴＩＯＮＭｅｔａｌｈｙｄｒｉｄｅｓｈａｖｅｂｅｅｎｕｓｅｄａｓｎｅｇａｔｉｖｅｅｌｅｃｔｒｏｄｅｓｏｆｎｉｃｋｅｌ／ｍｅｔａｌｈｙｄｒｉｄｅｂａｔｅｒｉｅｓｉｎｐｌａｃｅｏｆｃａｄｍｉｕｍ，ｂｅｃａｕｓｅｏｆｔｈｅｉｒｈｉｇｈｅｎｅ...     

SURFACE CARBURIZATION OF TiAl BASED ALLOY

ＳＵＲＦＡＣＥＣＡＲＢＵＲＩＺＡＴＩＯＮＯＦＴｉＡｌＢＡＳＥＤＡＬＬＯＹ￥Ｈｕａｎｇ，Ｂａｉｙｕｎ；Ｈｅ，Ｙｕｅｈｕｉ；Ｑｕ，Ｘｕａｎｈｕｉ；Ｋｏｎｇ，Ｇａｏｎｉｎｇ（ＰｏｗｄｅｒＭｅｔａｌｌｕｒｇｙＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅ，Ｃｅｎｔｒａｌ...     

MICROSTRUCTURE AND MECHANICAL PROPERTIES OF A Ni_3Al-Fe BASED ALLOY

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.     

CRYOGENIC PROPERTIES AND PARAMAGNETISMANTIFERROMAGNETISM TRANSITION OF A γ-Fe-Mn-Al ALLOY

本文报道一种fcc结构的Fe-Mn-Al合金(Mn 25.6,Al 4.1,C 0.16,Si0.27 wt-％)在超低温的性能、组织结构与磁性转变。此合金在300—4 K间具有适宜的强度、较高的塑性、韧性与很稳定的奥氏体组织。300 K及4 K的磁化率x_v,分别为34.5×10~(-4)与22×10~(-4)。室温电阻率为105μΩ·cm,低温冷收缩率小于一般Fe-Cr-Ni奥氏体钢。其磁化率(x_v)-温度(T)曲线于320 K左右呈现峰值,dx/dT符号的改变表征发生了顺磁性-反铁磁性转变。同时伴有一些物理性能如弹性模量、热膨胀、电阻率等的反常变化。 Al加入Fe-Mn合金中,明显地降低Néel温度(T_N),提高磁化率,并在T_N点处呈现较大的磁化率峰值。与AISI 300系Cr-Ni奥氏体钢比较,γ-Fe-Mn-Al合金的主要特点为在极低温区(如20—4 K)兼具稳定的奥氏体与极低磁化率,是一种潜在的超导磁体用结构合金。     

TEXTURE AND MECHANICAL PROPERTIES OF WARM ROLLED Fe_3Al BASED ALLOY

ＴＥＸＴＵＲＥＡＮＤＭＥＣＨＡＮＩＣＡＬＰＲＯＰＥＲＴＩＥＳＯＦＷＡＲＭＲＯＬＬＥＤＦｅ_３ＡｌＢＡＳＥＤＡＬＬＯＹＳＵＮＺｕｑｉｎｇ，ＭＡＯＷｅｉｍｉｎ，ＣＨＡＩＳｈｕｙａｎ，ＹＡＮＧＷａｎｇｙｕｅ，ＨＵＡＮＧＹｕａｎｄｉｎｇ（Ｕｎｉｖｅｒｓｉｔｙ...     

CALCULATION OF THE DAMPING OF THE Zn-27Al ALLOY BASED ON THE MICRO INTERFACE SLIDING MODEL

The microstructures of the Zn-27Al alloy after modification, solid-solution treatment, and natural aging were studied. It was clarified why the damping properties of Zn-27Al alloys, after treatment, had advanced most on the basis of analyzing the microstructures. Approximate expressions have been educed, which can be used to quantificationally work out the damping of the Zn-27Al alloy on the basis of the micro interface sliding model. By comparing the testing damping properties of the foundry Zn-27Al alloys and the Zn-27Al alloys after modification, solid solution, and natural aging, it was shown that the expressions were rational.     

TRANSFORMATION KINETICS AND COARSENING OF LAMELLAR STRUCTURE IN γ-TiAl ALLOY

研究了Ｔｉ－４７．８ａｔ．－％Ａｌ合金从α相区冷至室温再在双相区时效后，层状组织的转变机理及不连续粗化．层状组织转变过程与时效温度和形成过饱和α＿２单相时的冷却速度有关．建立了层状组织转变的动力学模型．层状组织的稳定性随片间距减小而降低，表现为时效时发生不连续粗化．     

MICROSTRUCTURE AND DECOMPOSITION OF RS Al-Fe-Cr-Zr ALLOY

ＭＩＣＲＯＳＴＲＵＣＴＵＲＥＡＮＤＤＥＣＯＭＰＯＳＩＴＩＯＮＯＦＲＳＡｌ－Ｆｅ－Ｃｒ－ＺｒＡＬＬＯＹ￥ＸｉａｏＹｕｄｅ；ＬｉＳｈｏｎｇｒｕｉ；ＸｉｅＹｏｎｇａｎ；ＸｕＹｉｈｅｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉ...     

QUENCHING AND AGEING BEHAVIORS OF Mg-Li-Zn ALLOY

ＱＵＥＮＣＨＩＮＧＡＮＤＡＧＥＩＮＧＢＥＨＡＶＩＯＲＳＯＦＭｇＬｉＺｎＡＬＬＯＹ①ＬｅＱｉｃｈｉ，ＣｕｉＪｉａｎｚｈｏｎｇ，ＬｉｕＨａｎｗｕＤｅｐａｒｔｍｅｎｔｏｆＭｅｔａｌＦｏｒｍｉｎｇ，ＳｃｈｏｌｏｆＭａｔｅｒｉａｌａｎｄＭｅｔａｌｕｒｇｙ，...     

BREAKAGE MECHANISM OF TUNGSTEN BASED ALLOY BLOCK FOR ELECTRO-HEAT UPSETTING

The breakage mechanism of W-Ni-Fe alloy in the process of electro-heat upsetting studied both theoretically and experimetnally, and also the behaviors of crack formation and propagation were analysed. Alloy suffers from corrosion and thermal-mechanical fatigue mutual function. Simultaneously, the practical ways to improve the anvil life was discussed.     

GLASS TRANSITION AND THERMODYNAMIC FUNCTION OF ZrAlNiCuCo ALLOY

１ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｇｌａｓｔｒａｎｓｉｔｉｏｎａｓａｐｏｌｙｍｏｒｐｈｏｕｓｏｎｅ（ｒｅｑｕｉｒｉｎｇｅｑｕａｌｉｔｙｏｆｃｏｍｐｏｓｉｔｉｏｎｉｎａｌｐｈａｓｅｓ）ｎｅｅｄｓａｖｅｒｙｓｍａｌＥ（ａｃｔｉｖａｔｉｏｎｅｎｅｒｇｙ）ｗｉ...     

MICROSTRUCTURE AND PERFORMANCE OF Ni-Hf BRAZING FILLER ALLOY

In consideration of the envelopment of γ dendrites by the Hf-rich melts at the late period ofsolidification of the cast Ni-base superalloys containing Hf,a heat of brazing filler alloycomposed of Ni-18.6Co-4.5Cr-4.7 W-25.6Hf(wt-%)was prepared.This alloy ishypereutectic.γ phase is the leading phase in eutectic γ+Ni_5Hf and γ bars are surrounded byNi_5Hf phase.At the section perpendicular or parallel to the γ growing direction,the eutecticmorphology is cellular or laminar respectively.The content of Ni_5Hf in the alloy is 68.7v.-%.The compositions of primary and eutectic Ni_5Hf are very similar.Ni,Co and Hf are the mainelements and solubility of Cr and W in Ni_5Hf is very low.This alloy is an ideal brazing fillersuitable to the directional or single crystal superalloy,and the elements are beneficial tosuperalloys properties.This filler alloy is of low melting point and of good fluidity.After braz-ing at 1240℃,5 min+1190℃,I h in 10~(-3) Pa vacuum,the microstructure of bond is the sameas that of Hf-bearing superalloy.No Si and B contamination is involved.     

FORM AND EFFECT OF Zr IN CuCoBeZr ALLOY

Precipitation form of Zr in CuCoBeZr alloy during solidificotion.cooling and final aging,aswell as its effect on the high temperature properties have been studied and discussed.Resultsshow that during solidificotion and cooding.Zr precipitates as fine particle.Cu_3Zr,which pre-vents X-Cu grains from growing and provides more nuclei for CoBe and hence leads to finerprimary CoBe.Fine Cu_3Zr partrticles also precipitate during aging.Because Co_3Zr is difficult to coalesce at high temperatures,the recrystallization temper-uture increases and the high temperature mechanical properties improve.     

EFFECT OF γ-IRRADIATION ON CuZnAl SHAPE MEMORY ALLOY

用透射电子显微镜和正电子湮没等分析手段,研究了CuZnAl形状记忆合金的γ辐照效应,此合金经一定剂量的γ辐照后,马氏体转变温度明显提高,而形状记忆功能仍保持不变。     

EFFECT OF γ-IRRADIATION ON CuZnAl SHAPE MEMORY ALLOY

Effect of γ-irradiation on the shape memory alloy CuZnAl has been studied by the techniquesof TEM,positron annihilation etc..The martensitic transformation temperature of the alloyincreases obviously ofter γ-irradiation at a dose of 2×10~7 Gy but not for a dose of 1×10~7 Gy.The shape memory effect in both irradiated alloys remains unaffected.     

MICROSTRUCTURE CHARACTERISTICS OF A HIGH DUCTILITY γ-TiAL ALLOY

研究了Ｔｉ－３３Ａ－３ＣＲ－０．５Ｍｏ合金经包套锻复合热机械处理后的显微组织与力学性能。结果表明，合金经１２５０℃，４ｈ及控制冷却的最终热处理，可获得以均匀细小等轴γ晶粒为主，含少量β２相和少量α２相的亚双态组织。由于晶粒细化和晶界结构２改善，该合金室位伸适性达到５．０７％。     

EFFECT OF HETEROGENEOUS DISTRIBUTION OF C AND ALLOYING ELEMENTS ON γ/α′ TRANSFORMATION IN A Fe-Mn-Cr-C ALLOY

The heterogeneous distribution of C and metallic alloying elements as well as the phase com- position changes before and after cold deformation of an Fe-Mn-Cr-C alloy have been stu- died by the use of Mssbauer spectroscopy.The austenites without and with C and metallic alloying elements are found in the alloy in as-solid solution state.While the martensites with- out and with C and alloying elements may be induced by cold deformation.The transforma- tion from austenite to martensite in the alloy is confirmed via theoretical computation and ex- periments to be controlled by the number of covalent electron pairs forming covalent bond in austenitic crystal cell of the alloy.The formation of strong covalent bond between C and me- tallic elements can vigorously retard the γ/α' transformation.     

EFFECT OF HETEROGENEOUS DISTRIBUTION OF C AND ALLOYING ELEMENTS ON γ/α′ TRANSFORMATION IN A Fe-Mn-Cr-C ALLOY

用内转换Mossbauer谱分析了Fe-Mn-Cr-C合金冷变形前后合金元素原子与碳原子的不均匀分布和相组成。发现该合金在固溶处理状态时为两类奥氏体,即无碳奥氏体和含碳奥氏体;经变形诱发出不含碳与合金元素的无碳马氏体(类α-Fe)及含碳与合金元素的合金马氏体。理论计算和试验证实:该合金中奥氏体向马氏体转变是受奥氏体晶胞内共价键中共用电子对的数目(n_A值)大小所控制。合金元素原子与碳原子之间形成结合力较强的C-M_e共价键,这对合金马氏体的形成具有强烈的阻碍作用。     

CALCULATION OF α/γ EQUILIBRIUM PHASE BOUNDARY IN LOW ALLOY STEELS

本文根据现有文献中的数据,将Sharma等的规则溶液模型推广到多元系,计算了含Cr,Mn,Si的20Cr,30Cr,40Cr,40Mn2,20CrMn,35CrMn2,38Crsi以及30CrMnSi等低碳低合金钢在其两相区各温度下α和γ两相的平衡浓度、两相的相对量及A_(e3)温度。计算得到的一系列合金的A_(e3)温度与实验值A_(c3)吻合较好。     

EFFECTS OF Zn CONCENTRATION ON WETTABILITY OF Sn-Zn ALLOY ON Cu AND ON THE INTERFACIAL MICROSTRUCTURE BETWEEN Sn-Zn ALLOY AND Cu

The potential of using a hypoeutectic, instead of eutectic, Sn-Zn alloy as a lead-free solder has been discussed. The nonequilibrium melting behaviors of a series of Sn-Zn alloys were examined by differential thermal analysis. It was found that at a heating rate of 5℃/min, Sn-6.SZn exhibited no melting range. Dipping and spreading tests were carried out to characterize the wettability of Sn-Zn alloys on Cu. Both tests exhibited that Sn-6.5Zn has significantly better wettability on Cu than Sn-9Zn. The reaction layers formed during the spreading tests were examined. When the Zn concentration fell between 2.5wt%-9wt%, two reaction layers were formed at the interface, a thick and flat Cu5Zn8 adjacent to Cu and a thin and irregular Cu-Zn-Sn layer adjacent to the alloy. Only a Cu0Sn5 layer was formed when the Zn concentration decreased to 0.5wt%. The total thickness of the reaction layer（s） between the alloy and Cu was found to increase linearly with the Zn concentration.