Influence of Tungsten Nanopowders
on Enhancing the Aging Behavior
of a Copper–Chromium Alloy
Gongcheng Yao, Shuaihang Pan, and Xiaochun Li
Abstract Copper–chromium alloys are a class of high-strength high-conductivity
copper alloys. However, limited by the copper–chromium (Cu–Cr) phase diagram,
the strength of copper–chromium (Cu–Cr) alloys by precipitation-hardening has
reached a certain limit. Suitable nanoparticles incorporating into copper–chromium
(Cu–Cr) alloys, i.e., nano-treating, are expected to modify the aging behavior and
further improve their properties. In this study, copper–chromium (Cu–Cr) alloy
containing tungsten (W) nanoparticles was cast. The aging behavior of the nanotreated Cu-Cr and Cu–Cr counterparts is assessed. Tungsten (W) nanoparticles
accelerate the precipitation, leading to a significant reduction in the peak aging
time. Besides, the microhardness of the nano-treated copper–chromium (Cu–Cr)
is increased over Cu–Cr after 45-min aging. Cold rolling can further enhance the
microhardness of the nano-treated copper–chromium (Cu–Cr). Moreover, the nanotreated sample exhibits a much improved thermal stability. Thus, nano-treating the
copper–chromium (Cu–Cr) alloy by tungsten (W) nanoparticles is promising to
break the limits of current copper–chromium (Cu–Cr) alloys.
Keywords Cu–Cr · Tungsten nanoparticles · Aging
Introduction
Age-hardenable copper–chromium (Cu–Cr) alloys are a class of copper (Cu) alloys
finding widespread applications where high strength and high conductivity are
required, such as spot welding electrodes, heat exchangers, and railway contact wires
[1]. Their high strength arises from the formation of nanoscale chromium (Cr) precipitates in the matrix by the aging process, while the high conductivity is attributed to
G. Yao · X. Li (B)
Department of Materials Science and Engineering, University of California, Los Angeles, CA
90095, USA
e-mail: xcli@seas.ucla.edu
S. Pan · X. Li
Department of Mechanical and Aerospace Engineering, University of California, Los Angeles,
CA 90095, USA
© The Minerals, Metals & Materials Society 2021
T. S. Srivatsan et al. (eds.), Metal-Matrix Composites, The Minerals, Metals
& Materials Series, https://doi.org/10.1007/978-3-030-65249-4_8
123
on Enhancing the Aging Behavior
of a Copper–Chromium Alloy
Gongcheng Yao, Shuaihang Pan, and Xiaochun Li
Abstract Copper–chromium alloys are a class of high-strength high-conductivity
copper alloys. However, limited by the copper–chromium (Cu–Cr) phase diagram,
the strength of copper–chromium (Cu–Cr) alloys by precipitation-hardening has
reached a certain limit. Suitable nanoparticles incorporating into copper–chromium
(Cu–Cr) alloys, i.e., nano-treating, are expected to modify the aging behavior and
further improve their properties. In this study, copper–chromium (Cu–Cr) alloy
containing tungsten (W) nanoparticles was cast. The aging behavior of the nanotreated Cu-Cr and Cu–Cr counterparts is assessed. Tungsten (W) nanoparticles
accelerate the precipitation, leading to a significant reduction in the peak aging
time. Besides, the microhardness of the nano-treated copper–chromium (Cu–Cr)
is increased over Cu–Cr after 45-min aging. Cold rolling can further enhance the
microhardness of the nano-treated copper–chromium (Cu–Cr). Moreover, the nanotreated sample exhibits a much improved thermal stability. Thus, nano-treating the
copper–chromium (Cu–Cr) alloy by tungsten (W) nanoparticles is promising to
break the limits of current copper–chromium (Cu–Cr) alloys.
Keywords Cu–Cr · Tungsten nanoparticles · Aging
Introduction
Age-hardenable copper–chromium (Cu–Cr) alloys are a class of copper (Cu) alloys
finding widespread applications where high strength and high conductivity are
required, such as spot welding electrodes, heat exchangers, and railway contact wires
[1]. Their high strength arises from the formation of nanoscale chromium (Cr) precipitates in the matrix by the aging process, while the high conductivity is attributed to
G. Yao · X. Li (B)
Department of Materials Science and Engineering, University of California, Los Angeles, CA
90095, USA
e-mail: xcli@seas.ucla.edu
S. Pan · X. Li
Department of Mechanical and Aerospace Engineering, University of California, Los Angeles,
CA 90095, USA
© The Minerals, Metals & Materials Society 2021
T. S. Srivatsan et al. (eds.), Metal-Matrix Composites, The Minerals, Metals
& Materials Series, https://doi.org/10.1007/978-3-030-65249-4_8
123