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A process of heating-cooling combined mold horizontal continuous casting→cold rolling→solid-solution treatment was used to produce Cu-1.7 wt% Be alloy sheet, and the precipitation behavior, microstructure and properties of the Cu-1.7 wt% Be alloy sheet during aging were investigated. The results showed that the phase transformation sequence of the alloy during aging at 325 °C was GP zone→γ″→γ′→γ equilibrium phase. The reasonable aging parameters were aging temperature of 325 °C and aging time of 3 h, and the hardness, tensile strength and yield strength of the aged alloy reached the peak values of 375 HV, 1042 MPa and 778 MPa, which were 172%, 116%, and 255% higher than those of the solid-solution alloy, respectively, and the electrical conductivity was 22.4% IACS. The formation of a large number of dispersed nano-sized γ′ phase was mainly responsible for the high strength of the alloy. A dynamic model of aging precipitation was established and the yield strength of the peak-aged alloy was calculated by the strengthening model. The deviation of the calculated value (797 MPa) and the measured value (778 MPa) was 2.4%, and the strengthening mechanism of the peak-aged alloy was determined as the Orowan bypass mechanism.

Cr-rich precipitates with a bcc crystal structure are an equilibrium phase in high-strength Cu–Cr alloys. Metastable fcc Cr-rich precipitates that are coherent with a fcc Cu matrix were retained in a Cu–Cr–Zr–Ti alloy during ageing. Atom-probe tomography analysis revealed that Cr atoms exist in the core of the Cr-rich precipitates, whereas Zr atoms segregate on the periphery. Fcc Cr-rich precipitates are prone to form because of the low nucleation barrier. A rapid diffusion of Ti atoms in the matrix stimulates the fcc Cr-rich nuclei growth. Resulting solute-lean zones hinder further nucleation of equilibrium bcc Cr-rich precipitates.

The decomposition of the thermodynamically metastable τ phase in MnAl has been studied using electron backscatter diffraction. The results showed that the nucleation of the equilibrium phase, β-Mn, in mechanically worked and recrystallized τ-Mn 54 Al 46 occurred preferentially at general grain boundaries, while twin-like defects displayed higher resistance against nucleation. Static recrystallization led to a change in the population of types of interface where the content of general grain boundaries is increased greatly. The reduced stability of mechanically worked τ compared to as-transformed τ is therefore attributed to a combination of recrystallization and selective nucleation at general grain boundaries.

The microstructure of a Cu-0.13 wt%Zr alloy cast or aged at 450–950 °C for 1 min–30 days (d) after solutionizing was investigated. Spherical fine precipitates having an ordered fcc lattice with a = 0.416 nm and a cube-on-cube orientation relationship to the Cu matrix were newly found in the cast alloy. Aging the alloy at 450 and 500 °C up to 30 d produced only disk-shaped Cu5Zr precipitates. In addition to the disk-shaped precipitates, the fine ordered fcc precipitates were formed in the alloy aged at 600–850 °C for a short time. The alloy aged at 900–950 °C for 1 min showed the coexistence of the fine fcc precipitates and coarse rod-shaped Cu5Zr precipitates of the equilibrium phase. Even after prolonged aging for 7–14 d at 600–950 °C, the fine fcc precipitates still remained together with the rod-shaped Cu5Zr precipitates of the equilibrium phase, indicating that the fcc precipitated phase is fairly stable at 600–950 °C. The aging time dependences of electrical resistivity at temperatures between 600 and 950 °C allowed us to obtain the solid solubility limits at these temperatures. The obtained solvus is coincident with the data reported previously.

The thermal stability of Al–32Mg and Al–42Mg alloys prepared by solidification under high pressures, which contain a large amount of Al(Mg) solid solution, was investigated in the present paper. With increasing Mg content in the Al(Mg) solid solution, the mechanism of phase transformation has a remarkable difference compared to that prepared by other techniques. The GP zones first dissolve, then the γ phase is formed; the stable β phase is finally formed during the heating of Al(Mg) solid solution. By comparing formation of the precipitation phase of Al(Mg) solid solution prepared by different methods, it can be concluded that vacancy concentration may determine whether the β′ phase is formed, and whether the high Mg content is the necessary condition for the formation of γ phase. The γ phases that are precipitated from the Al(Mg) solid solution and formed during the solidification process all transform to the β phase in the Al–32Mg alloy; however, a part of the γ phase stably exists in the Al–42Mg alloy according to the equilibrium phase diagram.

Electronic energy changes for the substitution of Mg atoms in the Mg8Si4 unit cell by Ca atoms and those for the substitution of Ca atoms in the Ca8Si4 unit cell by Mg atoms were calculated using density-functional theory to clarify the possible formation of a Mg2Si–Ca2Si solid solution with the expectation of a decrease in the concentration of donor-like positively charged Mg ions, the origin of persistent n-type conductivity in Mg2Si. CaMgSi with the Ca2Si-type structure, in which all the Ca atoms occupying one type of 4c site are completely substituted by Mg and all the other 4c sites remain occupied by Ca, is found to be energetically quite stable. This agrees with the observations that CaMgSi with this structure, usually referred to as the TiNiSi-type structure, is the only equilibrium phase in the Ca2Si–Mg2Si pseudobinary system. Electronic structure calculations of this phase showed that it is semimetallic, even though both Ca2Si and Mg2Si are semiconductors.

As-cast Mg–9Li–3Al(LA93) and Mg–9Li–6Al(LA96) alloys were prepared under the ambient of pure argon, and the effect of solution treatment and room temperature (RT) aging on the microstructure and microhardness of the alloys were investigated. The results show that the main phase compositions of the two alloys both consist of α(Mg), β(Li), AlLi phase, besides that there is θ(MgLi2Al) phase in LA96. After solid solution treatment, AlLi phase can completely be dissolved into the matrix, while θ phase is not fully dissolved into the matrix. In LA93 and LA96 alloys, AlLi phase precipitates from matrix during the 24 h RT aging. When the aging time increases to 48 h, more AlLi phase turns up and appears to aggregate which results in the decrease of hardness, and the transformation of θ phase into the equilibrium phase (AlLi) in LA96 also causes the hardness decrease.

Using a molten salt method, EMF measurements have been obtained for In–Sb, Sb–Sn and In–Sb–Sn alloys. New DSC experiments on Sb–Sn system gave a confirmation of the proposed Sb–Sn equilibrium phase diagram. A thermodynamic description of the ternary liquid in fair agreement with the experimental results has been obtained from the geometrical Muggianu approach.

Equilibrium phase diagrams have been established from X-ray phase analysis for the ternary systems NdCo(Nb, Mo, Ta, W, Re)Ge at 870 K and the crystal structure of the compounds which exist in these systems have been studied by X-ray structure analysis. Furthermore, analyzing recent results of investigations of the interaction of neodymium with d-elements and germanium, the influence of the M-component on the character of the phase diagram (M is a d-element) has been examined and a systematization of the crystal structures of ternary germanides of neodymium has been carried out.

Investigation of a series of AlCo(Cu,Ni) alloys of composition adjacent to Al3Co is reported. The metastable nature of the AlCo decagonal phase produced by rapid solidification was confirmed. This phase was found to form preferentially at compositions of about 72–74 at.% Al. At lower cooling rates, achievable by conventional solidification, decagonal-like metastable structures can be formed in the same compositional range, corresponding to the binary Al5Co2Z range of the equilibrium phase diagram (Grushko et al., J. Alloys Comp., 233 (1996) 279). The relation between these binary phases and the stable decagonal phases in AlCoCu and AlCoNi is discussed.

Equilibrium phase diagrams for the ternary systems Nd–{Cr,Fe,Co,Zn}–Sb at 870 K have been determined and analyzed for the first time. The phase field distributions in these systems at 870 K are characterized by the presence of only a small number of ternary compounds: For M=Cr, Fe, Co and Zn we observed one, two, and three ternary antimonides, respectively.

The complete Cd–Gd equilibrium phase diagram was investigated by a combination of powder-XRD, SEM and DTA. All previously reported phases, i.e., CdGd, Cd2Gd, Cd3Gd, Cd45Gd11, Cd58Gd13, and Cd6Gd, could be confirmed. In addition, a new intermetallic compound with a stoichiometric composition corresponding to “Cd8Gd” was found to exist. It was obtained that “Cd8Gd” decomposes peritectically at 465 °C. Homogeneity ranges of all intermetallic compounds were determined at distinct temperatures. In addition, the maximum solubilities of Cd in the low- and high-temperature modifications of Gd were determined precisely as 4.6 and 22.6 at.%, respectively. All invariant reaction temperatures (with the exception of the formation of Cd58Gd13) as well as liquidus temperatures were determined, most probably, Cd58Gd13 is formed in a peritectoid reaction from Cd45Gd11 and Cd6Gd at a temperature below 700 °C.