Among the copper alloys, the Cu-3Ag-0.5Zr alloy is one of the potential candidates for combustion chamber of liquid rocket engine because of its optimum combination of high strength with thermal conductivity. The present study is a detailed characterization of microstructure, strength, and electrical conductivity during the aging treatment. The aging cycle for Cu-3Ag-0.5Zr alloy after the solution treatment (ST) was optimized to obtain higher hardness without compromising on electrical conductivity. The precipitates responsible for strengthening in aged samples are identified as nanocrystalline Ag precipitates with an average diameter of 9.0±2.0 nm. © (2012) Trans Tech Publications.

Ravi Sankar Kottada

Department of Metallurgical and Materials Engineering

AGING CYCLE

AGING TREATMENT

Average diameter

CU-AG-ZR

Electrical conductivity

High strength

Liquid rocket engines

METALS AND ALLOYS

NANOCRYSTALLINE AG

OPTIMUM COMBINATION

SOLUTION TREATMENTS

Combustion chambers

electric conductivity

Electron microscopy

Industrial engineering

Metallurgy

Production engineering

Rocket engines

Silver

Zirconium

Zirconium alloys

Age hardening

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Materials Science Forum

A combination of high strength and good ductility was achieved in a precipitation hardenable Cu-3Ag-0.5Zr alloy through cryo-rolling (80% reduction in thickness) and aging in the temperature range (200-500 °C). The high-strength sheets produced by cryo-rolling showed a threefold increase in yield strength compared to that of the solution-treated and aged (220 MPa) sample, while retaining good ductility. An optimum combination of high strength (614 MPa) and ductility (8%) was achieved by 80% cryo-rolling and aging at 320 °C for 1 h. The high strength and good ductility obtained was attributed to various microstructural factors such as deformation twins, ultra-fine grains, high dislocation density and fine nano-sized silver precipitates. © 2016, ASM International.

Journal of Materials Engineering and Performance

High Strength and Good Ductility in Cu-3Ag-0.5Zr Alloy by Cryo-Rolling and Aging

The Cu-3Ag-0.5Zr alloy was produced by vacuum induction melting and subsequently processed through hot forging and rolling. Detailed microstructural characterization of solution-treated (ST) specimen shows three types of phases: Cu matrix, zirconium-rich phase, Cu-Ag-Zr intermetallic phase. Transmission electron microscopy studies together with energy-dispersive x-ray spectroscopy analysis established the presence of Zr-rich large particles in the ST condition. Aging at 450 C for 4.5 h after solution treatment resulted in the formation of uniformly distributed fine spherical silver precipitates with an average diameter of 9.0 ± 2.0 nm. Consequently, room temperature yield strength (YS) and ultimate tensile strength (UTS) of the aged specimen increased by 110% and 15%, respectively, compared to those of 120 and 290 MPa of the ST specimen. At elevated temperature, the YS decreased to 146 and 100 MPa at 540 and 640 C, respectively, for the aged sample. On the contrary, the YS increased to 140 MPa at 540 C, thereafter a decrease was observed with a value of 105 MPa at 640 C for the ST sample. This decrease in YS at higher temperatures is attributed to coarsening of precipitates and dissolution of the precipitates, whereas an increase in YS is attributed to in-situ aging of the samples. © 2013 ASM International.

Microstructure and mechanical properties of Cu-Ag-Zr alloy

Age-hardening characteristics of cu-3ag-0.5zr alloy

10.4028/www.scientific.net/msf.710

Materials Science and Engineering: A

Effect of Zr additions on the microstructure, and the mechanical and electrical properties of Cu–7 wt.%Ag alloys

Acta Materialia

Strengthening in rapidly solidified age hardened CuCr and CuCrZr alloys

Journal of Nuclear Materials

A survey of the properties of copper alloys for use as fusion reactor materials

Journal	Materials Science Forum
ISSN	02555476
Open Access	No