Thermoanalytical and dilatometric studies of the Al2O3\u2013Cu\u2013Mo hybrid composite

J Zygmuntowicz,P Piotrkiewicz,W Kaszuwara,M Wachowski,M Piątek

doi:10.1007/s10973-020-09526-w

Abstract

The present research is focused on the characterization of the composites from Al2O3–Cu–Mo system. The composites were prepared by slip casting method and subsequent sintering of green bodies in a reduced atmosphere. Two series of samples with different volume content of metallic powders were produced in the work: 10 vol% and 15 vol% of metal content with respect to the total solid-phase content. The sintering process of the composites was analyzed in detail. The linear shrinkage of the composites was measured. The shrinkage curves were obtained by dilatometry test in a heating mode. The composites were characterized by DTA/TG analyses and thermal conductivity. The composites were characterized by XRD, SEM, and EDX. The hardness was measured by Vickers hardness tester. Moreover, the Brazilian test was performed to determine the tensile mechanical properties of the composites. Fractography investigation was carried out as well. Dilatometric tests showed that the increase of the metallic phase volume in the ceramic matrix causes a decrease in the starting temperature of densification. Simultaneously, dilatometric experiments indicated that an increasing amount of metallic particles into the ceramic matrix increases the temperature of maximum densification and decreases the total shrinkage of the composites during sintering. The DTA/TG showed the characteristics of the dispersant decomposition to the atmosphere during thermal treatment and increase of mass connected with the oxidation of metals. Fractography results revealed good adhesion between Al2O3 matrix and the metallic phase. The observation allowed to conclude that the Al2O3 matrix surface is characterized by the brittle fracture mechanism.

Highlights

The current literature knowledge indicates that hybrid composites can be obtained using a variety of methods
The experimental results indicate that an increase in the metallic phase content in the composite leads to increased tensile strength
Two series of A l2O3–Cu–Mo composites with different content of metal phases were formed via the slip casting technique

Summary

Introduction

The current literature knowledge indicates that hybrid composites can be obtained using a variety of methods. The maximum densification rate for the pure Al2O3 samples is at about 1276 °C, whereas this temperature is increased to 1325 °C and 1342 °C for the composites with 10 vol% (Series I) and 15 vol% (Series II) of metallic phase, respectively.

Results

Conclusion