Cu–15Ni–8Sn alloy is the best choice to replace beryllium bronze alloy. This alloy has unparalleled application value in aerospace, ocean engineering, electronic information, equipment manufacturing, and other fields. However, the application of Cu–15Ni–8Sn alloy is challenged and limited because of a series of problems in its preparation and processing, such as easy segregation, difficult deformation, and discontinuous precipitation. It is an effective way to improve the comprehensive properties of Cu–15Ni–8Sn alloy using alloying design and process optimization to control the as-cast, deformed, and heat-treated microstructures. At present, it is a hot spot for scholars to study. In this paper, the grade generation, system evolution, and preparation technology development of Cu–15Ni–8Sn alloy are comprehensively reviewed. The phase transformation sequence of the Cu–15Ni–8Sn alloy is discussed. The influence of the type, amount, and existing form of alloying elements on the strength of Cu–15Ni–8Sn alloy and its mechanism are systematically summarized. Furthermore, the latest research progress on the effects of solid solution, cold deformation, and aging on the phase structure transformation and mechanical properties of Cu–15Ni–8Sn alloy is summarized. Finally, the future development trend of the Cu–15Ni–8Sn alloy is projected. The research results of this paper can provide a reference for the control of the microstructure and properties of high-performance Cu–15Ni–8Sn alloys used in key fields, as well as the optimization of the preparation process and alloy composition.

At present, most studies focus on Cu-W composites with high W content (W content > 50 wt%), while there are only sporadic reports on Cu-W composites with low W content (W content < 50 wt%). In this work, Cu-W composites with different W contents (0, 10 wt%, 20 wt% and 30 wt%) were prepared, and the effects of W content on microstructure, density, hardness, electrical conductivity, strength and electrical contact properties were systematically studied, with the expectation of providing an experimental basis and theoretical support for expanding the application range of Cu-W composites with low W content. The results showed that, with the increase in W content, the Cu matrices divided into finer and more uniform grains; the density and electrical conductivity of Cu-W composites decreased; and the compressive yield strength and hardness gradually increased. As the content of W increased, the arc burning time of the Cu-W composite contacts began to fluctuate. There was a loss of both the cathode and the anode contacts of the pure Cu, but the mass transfer of the Cu-W composite contacts occurred as follows: the anode weight increases, while the cathode weight decreases. The addition of W particles changed the non-uniform ablation of the pure Cu, and the surface ablation of the Cu-W composite contacts remained uniform.

To improve the Al/Steel bimetallic interface, Eu was firstly added to the Al/Steel bimetallic interface made by liquid-solid casting. The effects of Eu addition on the microstructure, mechanical capacities, and rupture behavior of the Al/Steel bimetallic interface was studied in detail. As the addition of 0.1 wt.% Eu, the morphology of eutectic Si changed from coarse plate-like to fine fibrous and granular in Al-Si alloys, and the average thickness of the intermetallic compounds layer decreased to a minimum value of 7.96 μm. In addition, there was a more sudden drop of Fe in steel side and the Si in Al side was observed to be more than the other conditions. The addition of Eu did not change the kinds of intermetallic compounds in the Al/steel reaction layer, which was composed of Al₅Fe₂, τ₁-(Al, Si)₅Fe₃, Al₁₃Fe₄, τ₅-Al₇Fe₂Si, and τ₆-Al₉Fe₂Si₂ phases. The addition of the element Eu did not change the preferential orientation of the Al₅Fe₂, τ₁-(Al, Si)₅Fe₃, Al₁₃Fe₄, τ₅-Al₇Fe₂Si, and τ₆-Al₉Fe₂Si₂ phases, but refined the grain size of each phase and decreased the polar density of Al₅Fe₂ phase. Eu was mainly enriched in the front of the ternary compound layer (τ₆-Al₉Fe₂Si₂) near the Al side and steel matrix. The Fe and Al element distribution area tended to narrow in the interface after the addition of 0.1 wt.% Eu, which is probably because that Eu inhibits the spread of Al atoms along the c-axis direction of the Al₅Fe₂ phase and the growth of Al₁₃Fe₄, τ₅-Al₇Fe₂Si, and τ₆-Al₉Fe₂Si₂ phases. When the Eu content was 0.1 wt.%, the shear strength of the Al/Steel bimetal achieved a maximum of 31.21 MPa, which was 47% higher than the bimetal without Eu.

High chromium cast irons are commonly used as casting infiltration layers in the applications of wear resistance. The formation mechanism of the casting infiltration layer is essential to better develop the surface wear resistance materials using the casting infiltration method. In the present work, casting infiltration layers with various Cr contents were fabricated in situ on the surface of parent ZG45 steel. CALPHAD-type calculations using Thermo-Calc software, SEM, EDS and microhardness tests were performed to study the effect of Cr on the microstructure and hardness of casting infiltration layers. All the microstructures of casting infiltration layers were composed of pearlite matrix and eutectic M₇C₃ carbide. With the increase in Cr content from 7.01 wt.% to 17.20 wt.%, the amount of M₇C₃ carbide increased from 5.05 vol.% to 13.12 vol.%, resulting in the increment of microhardness. With the aid of simulations, the solidification behavior and formation mechanism of casting infiltration layers were revealed.

In this paper, the effect of Si (1, 3, 5, 6 wt.%) and P (5, 10, 15, 20, 30 ppm) content on the Si phase and solidification behavior of Al-40Zn-xSi alloys are investigated via phase diagram calculation, scanning electron microscopy (SEM) and synchrotron radiation real-time imaging. It is found that Si content has a great influence on the microstructures of Al-40Zn-xSi alloys, and two distinct primary phases were separated by a critical composition at 5.49 wt.% Si in the calculated phase diagram. The microstructure contained not only needle-like eutectic Si, but also blocky primary Si particles in “hypoeutectic” commercial-purity Al-40Zn-5Si alloys. However, the synchrotron radiation real-time imaging experiment showed that the primary phase was α-Al in commercial-purity Al-40Zn-5Si alloys. The effect of P on the Si phase of the high-purity Al-40Zn-5Si alloy was also studied, showing that the number and size of the blocky primary Si particles in the high-purity “hypoeutectic” Al-40Zn-5Si alloys were mainly related to the P impurity content. A small minority of primary Si particles were found during the whole solidification process of the high-purity Al-40Zn-5Si alloy without P impurities, while a large number of primary Si particles were precipitated continuously at the front of α-Al dendrites in the high-purity Al-40Zn-5Si alloy with the addition of 20ppm P, which may have been caused by the fact that AlP particles can act as the heterogeneous nucleation sites of primary Si particles by a small undercooling in P-impurity-containing alloys.