Al-Zn-Cu系中的T'化合物与低Cu侧室温相关系

按热力学计算得到的Al5Cu4Zn的化学计量比成分,可以获得由温至400℃均为稳态单相的三元化合物T‘相合金。利用扫描电镜,电子探针和X射线衍射实验确定了Al-Zn-Cu系在室温下存在稳态Al Zn T‘三相区,而不存在稳态的Al Zn CuZn4三相区。明确了CuZn4是一种亚稳化合物,最终将转变为T‘相。确定了Al-Zn-Cu系室温下存在稳态的T‘ CuZn4两相区。     

Al-Zn-Cu系200℃低铜侧的相平衡

熔制了Al-Zn-Cu系的1 3个不同成分的合金,并进行了组织均匀化和平衡冷却至200℃的缓冷处理.通过显微组织观察、X射线衍射分析和电子探针微区成分分析,测定了这13个合金的相组成及成分.结果表明,在200℃时,富铝角a相的Zn、Cu、Al含量(摩尔分数)分别为6.7%、2.0%和91.3%,确定了T'相的成分范围以及Al2Cu3相中Zn的溶解度(摩尔分数)小于4.4%,绘制出了Al-Zn-Cu系200℃低Cu侧的等温截面相图.     

Cu—Co—Ge三元系室温相图

本文用X射线衍射法测定了Cu-Co-Ge三元系相图的室温截面。这个室温截面由九个单相区、十五个二相区和七个三相区所组成。九个单相区是:α(Cu),ζ(Cu_5Ge)、ε_1(Cu_3Ge)、β(Ge)、λ(CoGe_2)、δ(Co_5Ge_2)、τ(CoGe)、θ(Co_5Ge_3)和γ(Co);十五个二相区是:α ζ、ζ ε_1、 β、β λ、λ δ、δ τ、τ θ、θ γ、γ α、α θ、ζ θ、ε_1 θ、ε_1 δ、ε_1 λ和δ θ;七个三相区是:α γ θ、α θ ζ、ζ θ ε_1、ε_1 θ δ,ε_1 δ λ、ε_1 β λ和δ θ τ。截面中没有发现新相。     

应力对Al-Zn-Cu系平衡相的影响

采用99.999%分析纯的Al、Zn、Cu作原料,在外热式坩埚炉中熔制了5Cu40Zn55Al、15Cu20Zn65Al和3Cu17Zn80Al共3种合金,将其经过成分均匀化处理后,对包含亚稳相的3种合金分别进行球磨和手工锤击实验,采用X射线衍射仪分析合金平衡相组合。结果表明：合金通过球磨能得到室温平衡相,而通过手工捶击则得不到室温平衡相;能否通过应力诱发相变快速获得室温合金平衡相组织与合金应力作用产生的变形机制有关;球磨能使合金内部发生大量变形,为合金向平衡相转变提供驱动力和原子扩散通道;而手工锤击主要是使合金发生以解理为主的脆性断裂,这种变形不能为亚稳相的转变提供必要的驱动力和原子扩散通道,从而得不到合金室温下的平衡相组成。     

STUDY ON THE STABILITY OF T＇ PHASE IN THE Al-Zn-Cu TERNARY SYSTEM

The phase constitutes and phase compositions in the eight alloys designed with different compositions of Al-Zn-Cu system have been determined after the homogenous treatment and then equilibrium cooling to 20~C by use of optical microscope, electron probe microanalysis and X-ray diffraction. It has been found that there existed the T‘phase in the seven alloys. Consequently, it was testified that the T‘ phase was stable at room temperature. At the same time, the phase relationship was not locally right for the isothermal section of 20℃ of Al-Zn-Cu system of the ASM published in 1997.     

W-Ni-Cu三元系相图1017℃等温截面

采用扩散偶试样,借助电子探针、X射线衍射等分析方法,测定了W-Ni-Cu三元系1017℃等温截面。在该温度下,W-Ni二元系存在体心四方结构的Ni_4W和正交结构的NiW,没有观察到NiW_2。钨在Ni_4W中的固溶度范围为16.95—20.51at.-％(39.00—44.70wt-％),Cu在Ni_4W中的固溶度范围为0—4.36at.-％(3.40wt-％).钨在γ(Ni)固溶体中的最大固溶度为13.11at.-％ (32.10wt-％).     

Al-Cu-Sb三元系相图410℃等温截面

本文用X射线粉末衍射法和电子探针法测定了Al-Cu-Sb三元系相图的410℃等温截面。该截面由12个单相区、21个两相区和10个三相区构成。     

Au-Ag-Gd(Gd≤33.3%)三元系合金相图700℃等温截面

采用X射线衍射、DTA差热分析和显微金相分析等方法研究了Au—Ag—Gd三元系相图的富Au—Ag区域(Gd≤33．3％;原子数分数,下同),测定了Au—Ag—Gd三元系部分相图的700℃部分等温截面。该截面上有6个单相区：(Ag,Au),Ag51Gd14,Ag2Gd,Au2Gd,Gd14Au51和GdAu6;9个两相区：Ag51Gd14 (Ag,Au),Ag51Gd14 Ag2Gd,Ag2Gd Gd14Au51,(Ag,Au) AusGd,Ag2Gd Au2Gd,(Ag,Au) Gd14Au51,Ag51Gd14 Au2Gd,Gd14Au51 GdAu6和(Ag,Au) GdAu6;4个三相区：（Ag,Au) Gd14Au51 Au2Gd,Ag51Gd14 (Ag,Au) Au2Gd,Ag51Gd14 Ag2Gd Au2Gd和(Ag,Au) GdAu6 CdAu6 Gd14Au51。在该成份区域未发现新的三元化合物。     

Ag-Pd-Ru三元系相图的700 ℃等温截面

采用X射线衍射、电子探针和金相显微镜等方法研究了Ag-Pd-Ru三元系相图的700 ℃等温截面。发现在该截面上沿着Ag-Pd侧有一单相区(Ag或Pd),这个单相区在富Pd区域较宽;在该截面的富Ru侧也存在一较小的单相区(Ru);在这两个单相区之间是一个宽阔的二相区(Ag＋Ru)。此外,在Ag-Pd-Ru三元系富Ag-Ru侧的部分成分区域,由于合金在液态出现分层现象,凝固后难于获得均匀合金,致使该区域内的相区边界未能测定。     

Boundary trend of α1/(α1 +α2) phase region at lower Cu side in Al-Zn-Cu system

The range of miscibility gap above 300 ℃ at low Cu side in Al-Cu-Zn ternary system was obtained by EPMA of the designed alloys and diffusion-couples treated for equilibrium. The results about the boundary trend of the α1 / (α1 α2 ) phase region was obtained. The α1 / (α1 α2 ) boundary moves towards the lower Zn side with the increase of Cu content. The results are opposite to traditional phase diagrams obtained by experiments, but consistent with recent thermodynamic calculations.     

ROOM TEMPERATURE SECTION OF Cu-Dy(≤wt-%)-Ni TERNARY PHASE DIAGRAM

The room temperature section of Cu-Dy(≤35wt-%)-Ni phase diagram has been determinedby means of X-ray diffraction technique.The results are as follows.four single-phase regions(α,Dy_2Ni_(17),DyNi_5 and DyCu_5),five two-phase regions(α+Dy_2N_(17),Dy_2Ni_(17)+DyNi_5,DyCu_5+DyNi_5,α+DyNi_5 and DyCu_5+α)and two three-phase regions(α+Dy_2Ni_(17)+DyNi_5 and α+DyNi_5+DyCu_5)exist in the seetion.No any new phase was ob-servered.The solubility of Dy in α-phase is up to 2 wt-%.     

ROOM TEMPERATURE SECTION OF Cu-Dy(≤35wt-％)-Ni TERNARY PHASE DIAGRAM

本文用X射线衍射法对Cu-Dy-Ni(Dy≤35wt-％)三元合金系相图的室温截面作了测定。结果如下:它有4个单相区(α,Dy_2Ni_(17),DyNi_5和DyCu_5);5个两相区(α+Dy_2Ni_(17),Dy_2Ni_(17)+DyNi_5,DyCu_5+DyNi_5,α+DyNi_5和DyCu_5+α);和两个三相区(α+Dy_2Ni_(17)+DyNi_5和α+DyNi_5+DyCu_5)。没有发现新相。Dy在α相中的最大固溶度约为2wt-％Dy。     

ROOM TEMPERATURE AND 750℃ ISOTHERMAL SECTIONS OF Ag-Pd-Gd TERNARY SYSTEM (Gd≤25 at.-％) PHASE DIAGRAM

采用X射线衍射和金相显微镜分析方法研究了含0—25at.-％Gd的Ag-Pd-Gd三元系,作出了该体系部分相图的750℃等温截面和室温截面。发现在该二截面上都分别存在三个单相区、三个两相区和一个三相区。     

ROOM TEMPERATURE AND 750℃ ISOTHERMAL SECTION OF Ag-Pd-Gd(Gd≤25 AT.-%)PHASE DIAGRAM

The room temperature section and the 750℃ isothermal section of the Ag-Pd-Gd ternaryphase diagram containing 0—25 at.-% Gd are constructed by X—ray diffraction analysis andoptical microscopy.Each section consists of 3 single phase regions,3 bi-phase regions and Itri-phase region respectively.     

Thermodynamic aspects of TiAl and TiSi2 oxidation: The Al-Ti-O and Si-Ti-O Phase diagrams

Thermodynamic data from the literature were used to calculate the activity variations of Ti and Al in the Ti-Al system at 700, 900, and 1100°C and of Ti and Si in the Ti-Si system at 800, 1000, and 1300°C. The activity data were then applied to estimate the stable oxide phase in equilibrium with the metal phase, assuming that the activity of the oxide phase was unity. It was found that in the Ti-Al-O system the stable oxide changed from TiO to Al ₂O₃ in the existence region of the TiAl phase, while in the Ti-Si-O system a comparable change from Ti-oxide to SiO ₂ occurred in the existence region of the Ti ₅Si₃ phase. The significance of these results to the oxidation of intermetallics in the Ti-Al and Ti-Si systems is discussed briefly.     

EuCl3-KCl二元系相图

利用差热分析法研究了EuCl3 KCl二元系相图 ,发现该体系有两个固液同组成化合物EuCl3 ·3KCl和2EuCl3 ·KCl,体系相变点分别为 76 5℃ ,EuCl3 2 5 %(摩尔分数 )和 5 5 5℃ ,EuCl3 6 6 .7%(摩尔分数 ) ;一个异分熔化化合物EuCl3 ·2KCl,转熔点为 5 6 4℃ ,EuCl3 42 %(摩尔分数 ) ;3个低共熔点分别为 6 5 0℃ ,EuCl3 12 %(摩尔分数 ) ,5 0 0℃ ,EuCl3 5 5 %(摩尔分数 )和 490℃ ,EuCl3 85 %(摩尔分数 )。同时探讨了相图的某些规律。