The Effects of Zn, Cu and Mg Elements on Ageing, Microstructure and Hardness in Al Alloys Produced by P/M Method

Abstract

In this study, two different compositions contain pure Al, Zn, Cu and Mg were produced by powder metallurgy. The powders were pressed under 800 MPa and sintered in purity argon atmosphere at 600ºC after pressing process. Solution heat treatment were applied to sintered samples at 480ºC and then rapid quenching was performed. For quenched samples; Ageing process was carried out at 120ºC for 3h periods totally 12 hours. As a result, the ageing process leads to increased hardness due to the homogeneously dispersed secondary precipitates that form internally in the microstructure. Figure A. Circuit schema of the production processPurpose: The purpose of this study is investigation on effect of alloy elements on microstructure and hardness properties for Al alloy. Theory and Methods:The grinding process of the powders was carried out in Alcohol for 120 minutes. The powders were pressed under 800 MPa and sintered in an atmosphere-controlled furnace (high purity argon atmosphere) at 600ºC after pressing process. Solution treating was carried out at 480ºC for 2 hours. Field Emission Scanning Electron Microscopy (FESEM), Element Distribution Spectrometry (EDS) and Mapping (MAP) was used for microstructure analysis of the samples. Results:It is observed that the hardness values increase significantly after the ageing heat treatments for both alloys. In addition, after the solution process, while the hardness values of the alloy 1 was 130 HV, the hardness value of the alloy 2 increased up to 146 HV. The reason of this is Cu content that plays vital role in hardness of Al alloy. Conclusion:Ternary Al alloy was produced by PM in the different compositions. The effects of the alloying elements on the hardness and microstructure were examined. The study shows that the hardness increases in the alloy 2 due to the homogeneously dispersed Cu and secondary phases (such as Al2Cu) formed after heat treatments.

The effect of aging processes on tribo-metallurgy properties of al based ternary alloys product by P/M technique

“…In the study, high purity Al, Cu, Mg and Zn powders were alloyed by the MA method and three different compositions with an Al matrix were produced. The compositions of the samples were obtained by developing findings from a previous study [23]. The composition of the samples is given in Table I.…”