Analysis of the Influence of Starting Materials and Processing Conditions on the Properties of W/Cu Alloys

Isabel Montealegre-Meléndez; Cristina Arévalo; Eva M Perez-Soriano; Erich Neubauer; Cristina Rubio-Escudero; Michael Kitzmantel

doi:10.3390/ma10020142

Analysis of the Influence of Starting Materials and Processing Conditions on the Properties of W/Cu Alloys

Materials (Basel). 2017 Feb 8;10(2):142. doi: 10.3390/ma10020142.

Authors

Isabel Montealegre-Meléndez¹, Cristina Arévalo², Eva M Perez-Soriano³, Erich Neubauer⁴, Cristina Rubio-Escudero⁵, Michael Kitzmantel⁶

Affiliations

¹ Department of Engineering and Materials Science and Transportation, School of Engineering, University of Seville, Camino de los Descubrimientos s/n, 41092 Seville, Spain. imontealegre@us.es.
² Department of Engineering and Materials Science and Transportation, School of Engineering, University of Seville, Camino de los Descubrimientos s/n, 41092 Seville, Spain. carevalo@us.es.
³ Department of Engineering and Materials Science and Transportation, School of Engineering, University of Seville, Camino de los Descubrimientos s/n, 41092 Seville, Spain. evamps@us.es.
⁴ RHP-Technology GmbH, Forschungs- und Technologiezentrum, 2444 Seibersdorf, Austria. erich.neubauer@rhp-technology.com.
⁵ Department of Computer Languages and Systems, University of Seville, Avenida Reina Mercedes s/n, 41012 Seville, Spain. crubioescudero@us.es.
⁶ RHP-Technology GmbH, Forschungs- und Technologiezentrum, 2444 Seibersdorf, Austria. michael.kitzmantel@rhp-technology.com.

Abstract

In this work, a study of the influence of the starting materials and the processing time used to develop W/Cu alloys is carried out. Regarding powder metallurgy as a promising fabrication route, the difficulties in producing W/Cu alloys motivated us to investigate the influential factors on the final properties of the most industrially demanding alloys: 85-W/15-Cu, 80-W/20-Cu, and 75-W/25-Cu alloys. Two different tungsten powders with large variation among their particle size-fine (W_f) and coarse (W_c) powders-were used for the preparation of W/Cu alloys. Three weight ratios of fine and coarse (W_f:W_c) tungsten particles were analyzed. These powders were labelled as "tungsten bimodal powders". The powder blends were consolidated by rapid sinter pressing (RSP) at 900 °C and 150 MPa, and were thus sintered and compacted simultaneously. The elemental powders and W/Cu alloys were studied by optical microscopy (OM) and scanning electron microscopy (SEM). Thermal conductivity, hardness, and densification were measured. Results showed that the synthesis of W/Cu using bimodal tungsten powders significantly affects the final alloy properties. The higher the tungsten content, the more noticeable the effect of the bimodal powder. The best bimodal W powder was the blend with 10 wt % of fine tungsten particles (10-W_f:90-W_c). These specimens present good values of densification and hardness, and higher values of thermal conductivity than other bimodal mixtures.

Keywords: Rapid Sinter Pressing (RSP); microstructure; thermal conductivity; tungsten-copper alloys.