Investigation of nanocrystalline sintered W-25 wt% Cu composite. (February 2021)

• Record Type: Journal Article
• Authors: Mikó, T.; Kristály, F.; Pethő, D.; Svéda, M.; Karacs, G.; Gergely, G.; Gácsi, Z.; Roósz, A.
• Is Part Of: International journal of refractory metals & hard materials. Volume 95(2021)
• Publication Date: 2021-02
• Subjects: W-Cu composite -- Nano crystallite -- Planetary ball milling -- Pressing -- Sintering; Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2020.105438
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: W and Cu can be found in separate phases in the W-Cu composites since these elements do not dissolve in each other neither in liquid nor in solid phase, but with mechanical alloying it is possible to produce nonequilibrium W-Cu alloys In this work the nanostructured W-Cu composites were produced by planetary ball milling. The nanostructured W-Cu powder was sintered on 900 °C and 950 °C with 50 MPa pressure applied. The meso- and microstructure of the W-Cu powder and the sintered samples, were investigated with SEM, TEM and XRD. After 50 h of milling, the size of the W crystallites was ~10 nm, and about 10% of the Cu was solved in the W matrix, producing a W-Cu nonequilibrium alloy layer on the surface of W nano crystallites. During sintering, the Cu atoms left from the W surface to the Cu phases, so the W-Cu nonequilibrium alloy layer disappeared. The size of the W crystallites – after 60 min of sintering on 950 °C - was around 170 nm, and the relative density was ~90% of the theoretical density. Highlights: W-Cu nonequilibrium alloy layer developed on the surface of the W nano crystallites during milling. Due to W(Cu) formation the W peak became asymmetric, had lower intensity and its FWHM increased significantly. During sintering, the W-Cu nonequilibrium alloy layer disappeared. The crystallite size of W remained constant during sintering.