Investigation of the applicability of Cu-Fe-Mn-Ni based high entropy and compositionally complex alloys as metal matrix composites for cobalt free hot-pressed diamond tools

Due to the rising demand and carcinogenic effect of cobalt, alternative metal matrixes need to be developed for hot-pressed diamond tools. Due to this reason High-Entropy alloys without cobalt were calculated via phase fraction diagrams. Three alloys of the Al-Cu-Fe -Mn-Ni system Al30Cu30Fe5Mn25Ni10, Al11.25Cu35Fe5Mn20Ni28.75 and Al5Cu20Fe25Mn25Ni25 were chosen due to their different crystal structures ranging from pure bcc, eutectic fcc-bcc to pure fcc crystal structure. Cr5Cu20Fe25Mn25Ni25 was chosen to verify the change of one element on the consolidation properties. The alloys were mechanically alloyed and hot-pressed at 800 & DEG;C for 3 min without and at 900 & DEG;C for 3 min with diamonds. Porosity increased with the fraction of bcc solid solution in the investigated alloys of the Al -Cu-Fe-Mn-Ni system. Samples consisting of Cr5Cu20Fe25Mn25Ni25 showed the lowest porosity, which was attributed to precipitation of a second copper-rich fcc solid solution around the remaining pores. At a process temperature of 800 & DEG;C and 3 min isothermal hold the samples featured a porosity of only 2.72%. Within the XRD patterns and SEM images of the hot-pressed samples with diamonds no graphitization or formation of carbides could be observed. Therefore, Cr5Cu20Fe25Mn25Ni25 was identified as a promising cobalt free metal-matrix candidate for diamond tools. & COPY; 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

In response to the increasing demand and carcinogenic effect of cobalt, alternative metal matrixes without cobalt are developed for hot-pressed diamond tools. Through experimentation, Cr5Cu20Fe25Mn25Ni25 alloy is identified as a promising cobalt-free metal matrix material.