In this paper, a new high strength copper based alloy (Cu-20 at%Fe-5 at% Si) in Cu-Fe-Si system is reported that is designed by accessing submerged liquid miscibility gap of the Cu-Fe system and ternary addition of Si for a hierarchical design of microstructure. The alloy was synthesized by suction casting of the melt into a copper mould. This paper further elucidates the sequence of evolution of metastable phases in the microstructure due to non-equilibrium solidification through detailed characterizations of the microstructure of the alloy using transmission electron microscopy. The microstructure containing particles with globular morphology of the Fe-rich DO 3 ordered phase suggests its origin in the liquid state consistent with the expectation of a metastable liquid immiscibility. The solute rejection process during the later stage of solidification and the solid state cooling results in the evolution of Fe rich nano sized fully coherent ordered particles in the Cu-rich matrix. This particular alloy has achieved an excellent mechanical strength both at room temperature and at elevated temperature. The correlations between microstructure and mechanical behavior have been discussed in details.

Development of a new class of high strength copper alloy using immiscibility route in Cu-Fe-Si system: Evolution of hierarchical multi-scale microstructure

Tungsten inert gas cladding of steel substrate with copper alloy under different processing conditions was investigated with the particular emphasis on the influence of cladding current on the conc...

Investigation on TIG cladding of copper alloy on steel plate

Laser surface alloying (LSA) of pure copper on high nickel austenitic ductile iron was carried out using a 2 kW continuous wave (CW) CO 2 laser with two processing conditions: laser beam spot size D =5 mm, scanning speed V =2 mm s −1 , power density E =1.02×10 4 W cm −2 (condition 1) and D =2 mm, V =9 mm s −1 , 6.37×10 4 W cm −2 (condition 2). Microstructure in the alloyed zone was found to consist mainly of primary γ-austenite dendrites and an interdendritic eutectic of γ-austenite and M 7 C 3 carbides with copper wetting the dendritic boundaries. Distribution of the copper in the alloyed zone is fairly uniform across the depth of the pool and the concentration of copper in the alloyed zone highly depends on the power density. Copper spheroidal particles can be observed at the interdendritic boundaries under condition 1, indicating that the melt could be near the metastable miscibility gap and liquid phase separation (LPS) takes place due to rapid solidification. After LSA, hardness of the alloyed zone is considerably higher than before, which is attributed to both precipitation hardening and work hardening caused by the thermal stress.

Investigation of laser surface alloying of copper on high nickel austenitic ductile iron

Laser alloyed layers of Cu–Fe–Al–Si were prepared using an 8 kW $CO_2$ laser on copper substrate and a detailed TEM investigation of the cross-section microstructure was carried out. This paper elucidates on the sequence of evolution of various phases constituting a complex microstructure due to non-equilibrium solidification of the laser alloyed layer. The formation of micron size Fe-rich globules having $DO_3$ structure within Cu-rich fcc matrix suggests access to a submerged miscibility gap during the laser processing. The solute rejection processes during later stages of solidification and solid state cooling result in the evolution of submicron size Cu-rich dispersoids inside the Fe-rich globules and the Fe-rich nanoscale fully coherent precipitates within the surrounding Cu-rich matrix.

Microstructure evolution in laser alloyed layer of Cu–Fe–Al–Si on Cu substrate

Experimental investigation and thermodynamic calculations of the Al–Cu–Sb phase diagram

A four-parameter equation for determining the excess integral property of a binary system is deduced based on the Maclaurin infinite series. The series is expressed separately in the neighborhood of each of the pure components of the system. The components are subjected to appropriate boundary conditions at the various stages of the treatment. The present form of the function is found to be capable of interpreting thermodynamic properties of several relatively weakly interacting binary systems based on the present equation. The infinite dilution parameters compare favorably with the values reported in the literature.

B. Mazumdar

Papers

Thermodynamics of binary systems using interaction parameters

Machine learning based dynamic consensus model for predicting blood-brain barrier permeability