Novel processing of Ag-WC electrical contact materials using spark plasma sintering

• Published in: Materials & design 2017-05, Vol.121, p.262-271
• Main Authors: Ray, Nachiketa, Kempf, Bernd, Wiehl, Gunther, Mützel, Timo, Heringhaus, Frank, Froyen, Ludo, Vanmeensel, Kim, Vleugels, Jef
• Format: Article
• Language: English
• Subjects: Electron backscattered diffraction; Flexural strength; In-situ joining; Metal matrix composites; Powder metallurgy; Spark plasma sintering
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2017.02.070

Ag-WC (60-40wt%) contact materials based on three WC particle size powders were doped with 0.1wt% Ni and processed by an appropriate powder pre-treatment followed by spark plasma sintering (SPS). The contacts produced were already bonded to a copper profile during SPS in order to eliminate additional processing steps. The SPS composites had a more homogeneous microstructure and were tougher and softer than the materials produced by conventional press-sinter-infiltration. The infiltrated contacts had a lower arc-erosion whereas the contacts produced by both processes had a similar contact resistance. The microstructure after switching confirmed that the SPS materials had a porous contact surface layer and were crack-free in contrast to their press-sinter-infiltrated equivalents. [Display omitted] •Novel processing of Ag-WC (60-40wt%) contact materials by spark plasma sintering (SPS)•Single-step material densification and in-situ joining to copper substrate•Faster processing at lower temperatures•SPS composites are more homogeneous, tougher and softer than conventionally processed equivalents.