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.     

PHASE DIAGRAM OF SYSTEM NdCl_3-LiCl-KCl

The phase diagram of system NdCl_3-LiCl-KCl has been investigated by DTA.Six surfacescorresponding to the prhnary crystallization of NdCl_3,LiCl,KCl,γ-KCl·NdCl_3,β-3KCl·NdCl_3 and 2KCl·NdCl_3 respectively,eleven univariant lines related to the sec-ondary crystallization,two ternary eutectics E_1(70.5wt-% NdCl_3+8.0wt-% KCl,360℃)and E,(5.0wt-% NdCl_3+ 53.0wt-% KCl,355℃)and one ternary peritectic P(67.0wt-% NdCl_3+10.0wt-% KCl,375℃)were found.It is also chtrified that this studyon the system NdCl_3- KCl differs from previous work in the two transition temperatures:e_1(77.0 wt-% NdCl_3,484℃),e_2(40.0wt-% NdCl_3,620℃),p(70.0wt-%NdCl_3,610℃),3KCl·NdCl_3(690℃)and two reactions:α-3KGl·NdCl_3β-3KGl·NdCl_3 (355℃)β-SKGl·NdCl_3γ-3KCl·NdCl_3 (450℃)The eutectic point e_5(31.0wt-%LiCl,460C)is determined for the pseudobinary system3KCl·NdCl_3—LiCl.     

PHASE BOUNDARY OF α_2 PRECIPITATION IN Ti-Al-La TERNARY SYSTEM

The phase boundary,of α_2 precipitation at 600℃ in Ti-AI-La ternary system has been de-termined by TEM examination,which shows three kinds of phase regions,namely thesingle α phase region,the transitional phase region where there is superlattice reflection butno α_2 precipitation,and the α+α_2 region.A point of maximum aluminium content was foundto exist on the α/(α+α_2)boundary and the track of the boundary was explained in terms ofthe internal oxidation of lanthanum and the electron concentration rule for α_2 formation.     

PHASE EQUILIBRIA OF α_2(α)/γ IN Ti-Al-Nb TERNARY SYSTEM

ＰＨＡＳＥＥＱＵＩＬＩＢＲＩＡＯＦα２（α）／γＩＮＴｉＡｌＮｂＴＥＲＮＡＲＹＳＹＳＴＥＭ①ＤｉｎｇＪｉｎｊｕｎ，ＺｈａｏＧａｎｇ，ＨａｏＳｈｉｍｉｎｇＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｒｉｎｇＳｃｈｏｏｌ...     

α(α2)/γ PHASE EQUILIBRIA IN Ti-Al-C AND Ti-Al-B TERNARY SYSTEMS

α（α２）／γＰＨＡＳＥＥＱＵＩＬＩＢＲＩＡＩＮＴｉＡｌＣＡＮＤＴｉＡｌＢＴＥＲＮＡＲＹＳＹＳＴＥＭＳ①ＬｉＪｕｎｔａｏ，ＨａｏＳｈｉｍｉｎｇＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｒｉｎｇ，Ｎｏｒｔｈｅａｓ...     

PHASE BOUNDARY OF α_2 PRECIPITATION IN Ti-Al-La TERNARY SYSTEM

用透射电镜相分析方法测定了Ti-Al-La三元系在600℃等温截面上α_2相析出相界.结果表明,相界曲线上存在一个Al含量的极大点.根据α_2相形成的电子浓度规律和La的内氧化反应过程,定性地解释了实测相界的走向和Al含量极大点的出现.     

ISOTHERMAL SECTION OF PHASE DIAGRAM IN Ti-Al-Cr TERNARY SYSTEM AT 1000℃

应用多元扩散偶－电子探针微区分析技术及Ｘ射线衍射分析方法，测定了Ｔｉ－Ａｌ－Ｃｒ三元系相图１０００℃等温截面的含Ａｌ量达７５ａｔ．－％，含Ｃｒ量达７０ａｔ．－％的大部分区域。确定了Ｌｌ２结构的三元化合物相及其成分范围，完整地测定了ＴｉＡｌ，Ｔｉ３Ａｌ，ＴｉＡｌ２及ＴｉＡｌ３的相区范围及相平衡关系，明确了β－Ｔｉ相与ＴｉＣｒ２相的平衡关系及ＴｉＣｒ２相的成分范围     

PHASE EQUILIBRIUM RELATIONSHIPS OF α_2(α)/γ IN THE Ti-Al-Cr TERNARY SYSTEM

采用扩散偶－电子探针法系统测定了Ｔｉ－Ａｌ－Ｃｒ三元系１０００－１３００℃的α２（α）／γ相平衡关系和相平衡成分,给给出Ｃｒ含量小于１０％（原子分数）范围的Ｔｉ－Ａｌ－Ｃｒ三元系局部等温截面和Ｔｉ－Ａｌ局部纵截面相图,明确了Ｃｒ在α２（α）和γ相中分配比的变化规律,研究结果支持Ｃｒ在γＴｉＡｌ相中取代Ａｌ的位置,降低γ－ＴｉＡｌ相中Ａｌ含量的观点。     

STUDY ON γ/γ+NbC_x PHASE BOUNDARY IN Fe-Nb-C SYSTEM

<正> Nb是高强低合金钢的一个重要的微合金化元素。它与C,N及其它化合物在奥氏体中溶解度的大小,都直接影响钢的性能。了解γ/γ±NbC_x的平衡相边界,即溶度积〔Nb〕〔C〕~x很有必要,但目前已知的一批溶度积数据分歧很大,例如,     

EFFECT OF PROGRESSIVE AGING TREATMENT ON THE PROPERTIES AND MICROSTRUCTUR

ＥＦＦＥＣＴＯＦＰＲＯＧＲＥＳＳＩＶＥＡＧＩＮＧＴＲＥＡＴＭＥＮＴＯＮＯＮＴＨＥＰＲＯＰＥＲＴＩＥＳＡＮＤＭＩＣＲＯＳＴＲＵＣＴＵＲＥＯＦＴＨＥＨＩＧＨ－ＨＡＲＤＥＬＡＳＴＩＣＮＩＣＫＥＬ－ＣＨＲＯＭＩＵＭ－ＡＬＵＭＩＮＩＵＭＡＬＬＯＹ￥ＬＩＵＧｕｉ...     

ELEMENTAL PARTITIONING CHARACTERISTICS AND STABILITY OF EQUILIBRIUM PHASES DURING 450-1200℃ IN T/P91 HEAT-RESISTANT STEEL

利用Thermo-Calc软件计算了高Cr铁素体耐热钢T/P91在450-1200 ℃区间的 平衡相成分及其含量. 引入合金相元素分配量的概念, 研究了钢中Cr, Mo, Fe, V, Nb, C和N等主要元素随着温度变化在各平衡相中的分配特征、相稳定性、化 学组成及其演化规律. 结果表明, 利用相元素分配量随温度变化的特征, 便于揭 示不同温度区间M23C6及MX相的稳定性, 合理确定不同MX相的亚类型及 M和X的构成及演化规律. 此外, 有助于了解基体相含碳量的变化对 M23C6和MX相的影响.