Spinodal Alloys Research Articles

Strengthening complex concentrated alloy without ductility loss by 3D printed high-density coherent nanoparticles

Metallic 3D printing enables fast fabrication of net-shaped components for broad engineering applications, yet it restrains the use of most mechanical processing methods for strengthening alloys, e.g. forging, rolling, etc. Here, we proposed a new strategy for enhancing the strength of 3D printed complex concentrated alloys without losing ductility. This strategy relies on the rapid cooling of 3D printing to achieve a supersaturation state that is beyond conventional casting. Then, spinodal decomposition via aging is exploited to introduce high-density coherent nanoparticles for strengthening. The proposed strategy is demonstrated in a 3D printed Cu-based complex concentrated alloy. The rapid solidification during printing strongly inhibits elemental diffusion, leading to a high supersaturation state. High-density nanoparticles with coherent interface and size of ∼7 nm are introduced into the 3D printed samples through spinodal decomposition via simple aging treatment. The strength of the 3D printed alloy is increased by 30 % after aging with no ductility loss, leading to a strength-ductility combination superior to other Cu alloys. This strategy is readily applicable to other spinodal alloys fabricated by 3D printing for circumventing the strength-ductility trade-off dilemma.

The influence of microalloying and preparation process on phase transformation, mechanical properties, and friction/corrosion behavior of Cu–Ni–Sn alloys: A review

This review provides an overview of Cu–Ni–Sn alloys, which have great advantages as a potential substitute for beryllium bronze. The characteristics of spinodal decomposition in Cu–Ni–Sn alloys are thoroughly discussed by conducting a comprehensive analysis of thermodynamics and the phase diagram. The traditional casting process for Cu–Ni–Sn alloys is subject to several limitations, including segregation during solidification as a primary constraint. Another significant limitation is the occurrence of discontinuous precipitation during aging. Thus, the strategies to overcome these limitations are further elaborated. Commonly used methods include thermal-mechanical processing and composition design. Finally, the application of Cu–Ni–Sn alloys in friction and corrosion is discussed. The purpose of this review is to provide a comprehensive summary of the research progress and significant limitations encountered in Cu–Ni–Sn spinodal alloys. This includes a discussion of traditional casting methods as well as novel preparation techniques. The aim is to serve as a valuable reference for the development of new manufacturing methods and the future advancement of Cu–Ni–Sn spinodal alloys.

Influence of quenching medium on the dendrite morphology, hardness, and tribological behaviour of cast Cu–Ni–Sn spinodal alloy for defence application

Cu–Ni–Sn spinodal alloys (Spinodal bronze) are potential materials with robust applications in components associated with defence applications like bearings, propellers, bushes, and shafts of heavily loaded aircraft, off-road vehicles, and warships. This paper presents a comparative study using water, Brine solution, and SAE 40 oil as the quenching media in regular bronze (Cu–6Sn) and spinodal bronze (Cu–9Ni–6Sn) alloys. Morphological analysis was conducted by optical microscopy, transmission electron microscopy (TEM), and X-ray diffraction technique (XRD) on bronze and spinodal bronze samples immersed in the three different quenching media to understand the grain size and hardness values better. Tribological analysis was performed to analyze the effect of quenching media on the wear aspects of bronze and spinodal bronze samples. The hardness value of the brine-aged spinodal bronze samples was as high as 320 Hv, and the grain size was very low in the range of 60 μm. A quantitative comparison between brine-aged regular bronze and brine-aged spinodal bronze showed that the hardness (Hv) was almost 80% higher for brine-aged spinodal bronze. Further, the grain size was approximately 30% finer for spinodal bronze when compared with regular bronze. When the load was increased in spinodal bronze samples, there was an initial dip in wear rate followed by a marginal increase. There was a steady increase in friction coefficient with a rise in load for brine-aged regular bronze and spinodal bronze samples. These results indicate that brine solution is the most effective quenching medium for cast Cu–Ni–Sn spinodal alloys.

L. KLEIN DECLAFOR 1015

Abstract L. Klein Declafor 1015 is a ternary copper-nickel-tin spinodal alloy that combines high strength with excellent corrosion resistance and fair machinability. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: Cu-940. Producer or source: L. Klein SA.

Ultrastrong spinodoid alloys enabled by electrochemical dealloying and refilling

We present an extreme case of composition-modulated nanomaterial formed by selective etching (dealloying) and electrochemical refilling. The product is a coarse-grain polycrystal consisting of two interwoven nanophases, with identical crystal structures and a cube-on-cube relationship, separated by smoothly curved semicoherent interfaces with high-density misfit dislocations. This material resembles spinodal alloys structurally, but its synthesis and composition modulation are spinodal-independent. Our Cu/Au "spinodoid" alloy demonstrates superior mechanical properties such as near-theoretical strength and single-phase-like behavior, owing to its fine composition modulation, large-scale coherence of crystal lattice, and smoothly shaped three-dimensional (3D) interface morphology. As a unique extension of spinodal alloy, the spinodoid alloy reported here reveals a number of possibilities to modulate the material's structure and composition down to the nanoscale, such that further improved properties unmatchable by conventional materials can be achieved.

Focused Review on Cu–Ni–Sn Spinodal Alloys: From Casting to Additive Manufacturing

Focused Review on Cu–Ni–Sn Spinodal Alloys: From Casting to Additive Manufacturing

A study on the correlation between micro and magnetic domain structure of Cu52Ni34Fe14 spinodal alloys

Magnetic spinodal alloys are ideal materials for studying the relationship between the microstructure of an alloy and its magnetic properties. To unravel this relation, a profound knowledge of the chemical as well as the magnetic microstructure, i.e. the magnetic domain structure, is necessary. However, mapping the magnetic domain structure is rarely accomplished even though it is of major interest for both, fundamental research as well as applications using such alloys.In this study, the magnetic domain structure as well as the evolution of the microstructure of spinodally decomposed Cu52Ni34Fe14 alloys is investigated with various modern (scanning) transmission electron microscopy ((S)TEM) methods. The magnetic domain structure was mapped using differential phase contrast imaging (STEM DPC) and magnetic-force microscopy (MFM). The chemical microstructure was determined using high-angle annular dark field imaging (HAADF) and energy-dispersive X-ray spectroscopy (EDXS) elemental mapping.

Study of Stress Corrosion Cracking Resistance Of Copper Based Spinodal Alloys-Part 1

An investigation was conducted to evaluate the stress corrosion cracking resistance of copper based alloys. Cu, Ni, Sn of appropriate weight percentage were melted in a graphite crucible in an electric furnace under the argon atmosphere. The obtained specimens were solutionised and aged as per standards. The heat treated samples were subjected for microstructural evaluation and stress corrosion cracking test as per ASTM standard. In the microstructural analysis it was observed that the dendritic structure was completely vanished when the specimen was subjected to solutionising and aging. The stress corrosion cracking (SCC) was predominant in the regular bronze due to the formation of oxide layers according to the passive film rupture theory. But in the case of spinodal alloys only internal cracks were observed. These observed cracks were due to the pits and burrs present in the alloy

Effect of composition and aging time on hardness and wear behavior of Cu-Ni-Sn spinodal alloy

Copper alloyed with various compositions of nickel and tin were cast into molds under argon atmosphere. The cast rods were homogenized, solution heat treated, followed by aging for different time duration. The specimens were characterized for microstructure and tested for microhardness and wear rate. A hybrid model with a linear function and radial basis function was developed to analyze the influence of nickel, tin, and aging time on the microhardness and tribological behavior of copper-nickel-sin alloy system. The results indicate that increase in the composition of nickel and tin increases the microhardness and decreases the wear rate of the alloy. The increase in the concentration of nickel and tin decreases the peak aging time of the alloy system.

The impact of the surface morphology on optical features of the green emitting InGaN/GaN multiple quantum wells

AFM study of surface morphology in green LED structures and multifractal analysis allowed us to reveal a relationship between step-meandering morphology quantitatively characterized by a multifractal parameter, the degree of disorder, and features of In incorporation in InGaN/GaN MQW structures. These features manifest themselves in a shape of the distribution of peak external quantum efficiency values with wavelengths (DPEW) in the current range of 0.1–1000 mA. High values of degree of disorder result in spinodal alloy decomposition and/or local In enriched regions in InGaN alloy and in a twofold decrease in EQE values in green LEDs.

Precipitation evolution in Cu [Ni3Cr1] spinodal alloys under mismatch control

Abstract Cu Ni Cr alloys have a typical spinodal decomposition structure. However, a systematic investigation of the correlation between the mismatch of the two decomposition phases, Cu-rich (γ1) and Ni-rich (γ2), and the γ2 morphology is lacking. In this study, the microstructure evolution of Cux[Ni3Cr1] (x = 1, 2, 3, 4, 5, 7, 9, and 12) alloys was investigated over a wide composition range. The results show that mismatch significantly affects the shape of the γ2 precipitates. The γ2 phase is cubic when the mismatch degree (η) is in the range 0.62%–0.75% and lath-shaped when η is in the range 1.08%–1.35%. With increasing Cu content, the proportion of the lath-shaped γ2 phase decreases and that of the cubic γ2 phase continuously increases. Cubic precipitates enhance the alloy strength, while lath-shaped precipitates show better corrosion resistance owing to their high packing density. Therefore, an appropriate x can be chosen according to the actual service conditions. In addition, the Cr state affects the microstructure and performance of the alloys. Cr in the solid solution state promotes spinodal decomposition, while a large amount of Cr-rich precipitates at the grain boundaries has a negative effect on the mechanical performance.

Microstructure and tribological properties of plasma sprayed Cu-15Ni-8Sn coatings

Cu-15Ni-8Sn coatings were prepared using atmospheric plasma spraying. The influences of arc current and aging treatment on the microstructure, mechanical and tribological properties were investigated. The coating microstructure, the wear track and the wear debris were observed and analyzed. The melting state of the particles is improved by increasing of arc current. The hardness of the aged coatings is higher than the as-sprayed coatings. The wear resistance of the aged coatings is 3–4 times higher than the as-sprayed coatings. The continuous smooth tribolayer formed on the wear tracks contributes to the low wear rate of aged coatings. The dominant wear mechanism of the coatings is delamination coupled with spalling under dry sliding condition. This work provides an effective method for producing spinodal alloy coatings with enhanced mechanical and tribological properties.

Measurement of Mechanical Properties and Microstructure of Cu-Ni-Cr Spinodal Alloy

Measurement of Mechanical Properties and Microstructure of Cu-Ni-Cr Spinodal Alloy

The influence of sliding velocity and third bodies on the dry sliding wear of Fe30Ni20Mn25Al25 against AISI 347 stainless steel

The objectives of this work were to determine the influence of frictional heating on the wear of Fe30Ni20Mn25Al25, a recently developed nanostructured spinodal alloy with high strength and hardness, and to investigate the role played by third bodies (oxide wear debris and tribolayers) on the wear process. Pins of the subject alloy were tested in dry sliding against disks made from AISI 347 stainless steel. The tests were run in air at sliding velocities ranging from 0.1 to 1.0m/s. It was found that wear rates of the pin specimens were much lower at high sliding speeds (≥0.5m/s) than at lower speed, and wear rates at the high sliding speeds were higher when wear particles were swept continuously from the disk surface during the tests. Analysis of the worn surfaces and the wear debris indicated that oxidation had occurred within the sliding contacts as a result of high sliding contact temperatures. Those high temperatures also resulted in softening of the near surface material of the contacting pins and disk, enabling oxide debris and material that was worn and transferred from the counterface to be incorporated in a mechanically-mixed tribolayer on the pin surface. The hard tribolayer contributed to the reduction in wear rate at high sliding velocities.

Determination of optimum aging temperature and time, mechanical and wear properties for Cu-9Ni-6Sn spinodal bronze alloy cast using permanent mould

A detailed study was performed to find the optimum aging temperature and time for Cu-9Ni-6Sn spinodal alloy cast using permanent mould. The mechanical and wear properties of the alloy were determined and their variations with the aging temperature and time was researched for solutionised and aged condition. The as-cast dendritic structure was completely removed from the alloy after the heat treatment process. The top hardness was found to increase and then decreased with the aging temperatures and time. The optimum aging time and temperature for the Cu-9Ni-6Sn spinodal alloy were also determined. The tensile properties were found to be high when compared with that of the Cu-6Sn. The wear rate values exhibit a decrease with an increase in the hardness of the spinodal alloy. Characterisation of the spinodal alloy was conducted to discuss the wear mechanism and the fracture mode of the spinodal alloy.

High-Tc Layered Ferrielectric Crystals by Coherent Spinodal Decomposition.

Research in the rapidly developing field of 2D electronic materials has thus far been focused on metallic and semiconducting materials. However, complementary dielectric materials such as nonlinear dielectrics are needed to enable realistic device architectures. Candidate materials require tunable dielectric properties and pathways for heterostructure assembly. Here we report on a family of cation-deficient transition metal thiophosphates whose unique chemistry makes them a viable prospect for these applications. In these materials, naturally occurring ferrielectric heterostructures composed of centrosymmetric In4/3P2S6 and ferrielectrically active CuInP2S6 are realized by controllable chemical phase separation in van der Waals bonded single crystals. CuInP2S6 by itself is a layered ferrielectric with a ferrielectric transition temperature (Tc) just over room temperature, which rapidly decreases with homogeneous doping. Surprisingly, in our composite materials, the ferrielectric Tc of the polar CuInP2S6 phase increases. This effect is enabled by unique spinodal decomposition that retains the overall van der Waals layered morphology of the crystal, but chemically separates CuInP2S6 and In4/3P2S6 within each layer. The average spatial periodicity of the distinct chemical phases can be finely controlled by altering the composition and/or synthesis conditions. One intriguing prospect for such layered spinodal alloys is large volume synthesis of 2D in-plane heterostructures with periodically alternating polar and nonpolar phases.

AM388

Abstract AM388 is a copper-base spinodal alloy with high strength combined with formability. This datasheet provides information on composition, physical properties, hardness, tensile properties, and bend strength. It also includes information on forming and heat treating. Filing Code: Cu-843. Producer or source: AMETEK Specialty Metal Products.

Effects of temperature gradient on the interface microstructure and diffusion of diffusion couples: Phase-field simulation**Project supported by the National Natural Science Foundation of China (Grant No. 51571122) and the Fundamental Research Funds for the Central Universities, China (Grant No. 30920130121012).

The temporal interface microstructures and diffusions in the diffusion couples with the mutual interactions of the temperature gradient, concentration difference and initial aging time of the alloys are studied by phase-field simulation, and the diffusion couples are produced by the initial aged spinodal alloys with different compositions. Temporal composition evolution and volume fraction of the separated phase indicate the element diffusion direction through the interface under the temperature gradient. The increased temperature gradient induces a wide single-phase region on two sides of the interface. The uphill diffusion proceeds through the interface, no matter whether the diffusion direction is up or down with respect to the temperature gradient. For an alloy with short initial aging time, phase transformation accompanying the interdiffusion results in the straight interface with the single-phase regions on both sides. Compared with the temperature gradient, composition difference of diffusion couple and initial aging time of the alloy show greater effects on diffusion and interface microstructure.

A study on the effect of tin addition on wear and mechanical properties of spinodal alloys cast in metal mould

The goal of this study is to determine the mechanical and wear properties of spinodal alloys (Cu-Ni-Sn) cast in metal mould. Copper, nickel and tin of varying tin content were melted in a graphite crucible under argon atmosphere and were poured into a metal mould. The cast samples were solutionised at 825°C for 10 h and were aged at 250, 300, 350, 400 and 450°C for 1-5 h. The solutionised and aged specimens were subjected for microstructure evaluation, hardness, wear and tensile testing. It was observed from the study that the maximal hardness increases with increase in tin content. The wear rate was found to decrease with increase in tin content and coefficient of friction was found to be a constant irrespective of the tin content. The ultimate tensile strength and yield strength were found to increase with increase in tin content and percentage elongation was found to decrease with increase in tin content.

BRUSHFORM 158

Abstract BrushForm 158 is a spinodal alloy that develops exceptionally high elastic strength levels, dimensional stability, and relaxation resistance at high temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. and bend strength. It also includes information on forming. Filing Code: Cu-832. Producer or source: Materion Brush Performance Alloys.