The use of sodium silicate to improve wetting of tungsten carbide powder with ductile iron

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Nuno Lourenço (Author) FEUP; Henrique Santos (Author) FEUP; Carlos Sá (Author) FEUP

Journal

Title: Materials Science Forum

Vol. 587-588

Pages: 118-122

ISSN: 0255-5476

Publisher: Trans Tech Publications Ltd

Indexing

Scopus

INSPEC

COMPENDEX

Scientific classification

FOS: Engineering and technology

CORDIS: Technological sciences > Engineering > Materials engineering

Other information

DOI: 10.4028/www.scientific.net/MSF.587-588.118

Abstract (EN): A tungsten carbide insert is produced during ductile iron foundry practice to increase the surface hardness of the material. The insert is ensured with the help of a critical quantity of a binder, around 3 weight percent of sodium silicate, previously mixed with the tungsten carbide powder. The binder is verified to form a film around the tungsten carbide particles and bridges amongst these enveloped particles; these films and bridges are replaced by the ductile iron melt during the molding cavity filling. After solidification, a sound inserted layer is formed, composed of tungsten carbide particles in a tungsten enriched cast iron matrix. In the absence of the binder addition to the tungsten carbide powder no inserted layer is produced. The surface hardness of the inserted test pieces is close to 500VHN/4.9N and the respective thickness is around 2.5 mm. The characterization of the effect of the sodium silicate in the mixture has been the main purpose of this work

Language: English

Type (Professor's evaluation): Scientific