On the Mechanical Properties of Cooper–Al2O3 Cermets of a Low Reinforcing Level, Processed by Powder Metallurgy
There is investigated the influence of Al2O3 content on the density and mechanical properties of Cu-Al2O3 (2.0 ÷ 10.0 [vol.%] Al2O3) cermets processed by classical routes of powder metallurgy. The obtained results show that the cermets relative density remains quite constant, at a value of over 95 [%], up to a content of ~4 [vol.%] Al2O3. Together with reinforcing effect of the hard Al2O3 particles, proved by the apparition of an elastic zone on the Stress-Strain curve of tensile test, determine a notable increasing of ultimate tensile strength (UTS) and hardness with a small variation of elongation. Over about 4÷5 [vol.%] Al2O3, a decrease in UTS and also in toughness, proved by the Fracture energy decreasing, occurs. Consequently, from the considered points of view, is not recommended to adopt higher reinforcing levels. For electrical applications, the relative density of the processed cermets can be further increased with 3 ÷ 4 [%] by die cold repressing.
Ionel Chicinaş and Traian Canta
L. N. Mîtcă and R. L. Orban, "On the Mechanical Properties of Cooper–Al2O3 Cermets of a Low Reinforcing Level, Processed by Powder Metallurgy", Advanced Materials Research, Vol. 23, pp. 131-134, 2007