Thermomechanical Processing and Roll Bonding of Tri-Layered Cu-Ni-Zn/Cu-Cr/Cu-Ni-Zn Composite

2017

KEM

Self Cite

In the present study, the microstructural stability and mechanical properties of a MnFeCoNiCu alloy in which Cr was replaced by Cu from Cantor composition (CoCrFeMnNi) was studied. In the as-cast alloy, the dendrite arms are enriched with Cu and Mn and matrix between dendrite arms is enriched with Fe and Co. Ni was richer in the matrix, but also observed in the dendrite arms. Cu and Mn tend to segregate and solidify initially because the melting temperatures of Cu and Mn are lower than Fe and Co, resulting in the growth of Cu-Mn dendrite. After homogenization, the dendrites structure disappeared and grain boundaries are visible, indicating the segregated elements in the dendrite structure were homogenized. The presence of single phase FCC structure was confirmed after homogenization. The tensile strength of 1220 MPa with the ductility of 6 % was obtained in MnFeCoNiCu alloy.

Section: Resultsmentioning

confidence: 49%

Microstructural Evolution and Mechanical Properties in a Mn1.05Fe1.05CoNiCu0.9 High Entropy Alloy

2017

KEM

Self Cite

“…The material properties of Cu-based alloys [18] used for electrical or electronic applications are controlled by heat treatment, resulting in both high electrical and thermal conductivities and tensile strength [19]. However, Cu and Cu alloys are more expensive and have a higher specific weight than Al and Al alloys with lower conductivity.…”

Section: Introductionmentioning

confidence: 99%

Effect of Intermetallic Compound Layer on Peel Strength and Crack Propagation Behavior in Cu/Al/Cu Clad Composites

Kim

2019

Metals

Self Cite

The effects of interfacial modification in tri-layered Cu/Al/Cu composites by heat treatment on interface stability and crack propagation were investigated. In order to investigate the crack path during the peel test, the intermetallic compound layer with the propagating crack was examined using electron backscatter diffraction (EBSD) analyses. The increase of peel strength from 7.8 to 9.1 N/mm in the tri-layered Cu/Al/Cu composite in the presence of thin discontinuous intermetallic compounds with heat treatment at 200–300 °C was accompanied by the increase of electrical conductivity from 65.3% IACS (International Annealed Copper Standard) to 66.8% IACS. Continuous intermetallic layers consisting of Al2Cu, AlCu, and Al4Cu9 were found in Cu/Al/Cu heat-treated at temperatures above 350 °C and its thickness increased rapidly and reached up to 35.2 μm at 500 °C. The peel strength drastically decreased to 5.75 N/mm after heat treatment at 400 °C, and it gradually increased as the heat treatment temperature was increased to 450 °C (5.91 N/mm) and 500 °C (6.16 N/mm). The increased peel strengths after heat treatment at 450 and 500 °C were accompanied by pronounced serrations of the peel strength–displacement curves. The amplitude of serration increased substantially with increasing annealing temperature from 400 to 500 °C. The major crack along the interface propagated, mostly along the Al2Cu/AlCu boundary with some inclined cracks, propagated through the AlCu and Al4Cu9 intermetallic compound layers. The repetition of crack propagation along the interface and crack deflection through the intermetallic layer as an inclined crack induced the serrated surface on the peeled-off Cu plate, enhancing the interface toughening.

“…The clad manufacturing methods include rolling, extrusion, electro-plating, overlay welding and explosive welding. Among these methods, the rolling is one of the useful processes because of its low-cost and good productivity [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Among various clad metals, Cu and Al clad metals have been widely used because of their advantages associated with high strength and high conductivity of Cu and low density and moderate conductivity of Al [7,10].…”

Section: Introductionmentioning

confidence: 99%

Bending Behavior and Electrical Conductivity of Cu/Ni/Al/Ni/Cu Clad Composite

Kim

2017

MSF

In this study, electro nickel coating was applied and its effect on the electrical conductivity and mechanical properties was investigated in Cu/Ni/Al/Ni/Cu clad composite after annealing at various temperature. After annealing at 300OC for 3hrs, the interface reaction layer at the Cu/Al interface was observed to be 3μm and no reaction layer was observed at the Ni/Al interface. After annealing above 400OC for 3hrs, the interface reaction layer at the Cu/Al interface in the absence of Ni layer was observed to grow more rapidly with increase of annealing temperature compared to that at the Ni/Al interface. The electrical conductivity increased after annealing up to 300OC for 3 hrs. possibly because of enhanced interface bonding and the recovery in the matrix. However, it was deteriorated after annealing above 400OC for 3 hrs. because of the formation of interface intermetallic. The more localized bending in the as-roll-bonded clad composite and that annealed at 200°C can be attributed to the near-zero and negative hardening rate in bending over the whole displacement. In this case, once bending occurs, bending continue to occur in the localized region because the work hardening due to the localized bending is negligible, leading to the localized fracture.