The Microstructure and Mechanical Properties of Cu-20Ni-20Mn Alloy Fabricated by a Compact Preparation Process

2023

physics

The spontaneous infiltration method for fabricating composites was used, in which molten Cu–Ni–Mn–Fe binders penetrated W–C filler particles due to capillary forces. The metal matrix composites thus obtained were characterized for phase composition, microstructure, porosity and microhardness. All composites were studied in their as-prepared condition with further annealing at 900°С for 60 and 750 h. It was shown that the mechanism based on the dissolution/diffusion bonding of the particulate/matrix interface was in agreement with the results of this study. The interfacial reactions provided a driving force for wetting but did not give rise to unwanted phases that could degrade the properties of the composite materials. From the EDX measurements it was concluded that mainly Fe atoms diffused from the Cu–Ni–Mn–Fe binders into the WC phase of the eutectic (WC+W2C) filler. Dissolution of this phase resulted in the appearance of W2C layer at the interface. Annealing at 900°С significantly promoted the interfacial reaction especially during the first 60 h of heat treatment. The degree of the reaction between the molten Cu–Ni–Mn–Fe alloys and W–C particulate could be limited by controlling the iron content of the binders to obtain an optimal interface.

Section: Introductionmentioning

confidence: 99%

Physical-and-chemical processes at the interfaces of (Cu–Ni–Mn–Fe)/ (W–C) composites

2023

physics

“…The high strength of the Cu-Ni-Mn alloys is attained by precipitation hardening [16][17][18][19]. This process involves the formation of -NiMn phase from a supersaturated solid solution of alpha-copper.…”

Section: Introductionmentioning

confidence: 99%

The The effect of iron on precipitation hardening in the Cu-Ni-Mn alloys

2021

Phys. Chem. Solid St.

The peculiarities in the structure and properties formation of precipitation-hardened Сu–Ni–Mn–Fe alloys within the concentration range of Ni (19.3–21.0 %), Mn (19.5–20.5 %), Fe (0.6–2.7 %), Cu – balance (in wt. %) were investigated in this work. The methods of quantitative metallography, X-ray analysis, scanning electron microscopy, energy-dispersive spectroscopy and differential thermal analysis were applied. Two solid solutions based on a-Cu differing in composition and hardness were found in the structure of the cast Сu–Ni–Mn–Fe alloys. The temperature ranges of solutions’ formation were determined as (1010±10) °С and (890±10) °С, correspondingly. NiMn phase was also formed at (405±15) °С due to precipitation hardening. In the Сu–Ni–Mn–Fe alloys annealed at 500 and 900 °С for 60–750 hours, the volume fraction and size of NiMn precipitates increased with prolonging annealing time and lowering annealing temperature. As iron content was raised up to 2.7 wt. %, the density of NiMn precipitates increased, especially during first 60 hours of annealing at 900 °С. By adding iron, oxidation resistance was improved, but melting temperature and fluidity did not yield any significant change. Hardness of the Сu–Ni–Mn–Fe alloys with higher iron contents increased by 10 НRB on average. However, when test temperature was raised up to 400 °С, tensile strength decreased (by ~1.3 times) and elongation dropped markedly (by ~10 times).

“…The elevated strength of the Cu-20Ni-20Mn alloy is achieved by precipitation hardening [2]. This process involves the formation of -NiMn phase from a supersaturated solid solution of -Cu.…”

Section: Introductionmentioning

confidence: 99%

Structure and properties of precipitation-hardened Сu–Ni–Mn–Fe binders for composite coatings

Vashchynska²

2021

JPhysElectron

The structure and properties of Сu–Ni–Mn–Fe alloys within the concentration range of 19.3–21.0 % Ni, 19.5–20.5 % Mn, 0.6–2.7 % Fe, Cu – the balance (in wt. %) were studied in this work. Quantitative metallographic, X-ray, and differential thermal analyses were applied. Two α-Cu solid solutions that differ in composition and microhardness were revealed in the structure of the investigated Сu–Ni–Mn–Fe alloys. These solutions were formed at 1010 ± 10 °С and 890 ± 10 °С, correspondingly. Besides, hardening NiMn phase was precipitated at 405 ± 15 °С due to ageing. In the Сu–Ni–Mn–Fe alloys annealed at 900 °С for 60–750 hours, the volume fraction and size of NiMn precipitates increased with increasing holding time. When iron content was raised from 0.6 up to 2.7 wt. %, the amount of NiMn precipitates increased, especially during first 60 hours of annealing at 900 °С. Brinell hardness of the Сu–Ni–Mn–Fe alloys with higher iron contents increased by 10 НRB on average. At that, as test temperature was raised up to 400 °С, tensile strength decreased by ~1.3 times and elongation dropped markedly by ~10 times. The investigated Сu–Ni–Mn–Fe alloys containing up to 2.7 wt. % may be applied as binder materials for composite coatings provided that working temperature does not exceed 400 °С.