Thick b-SiC CVD-Coated SiC Die System for Dry Cold Forging of Metals

• Main Authors: Tatsuhiko Aizawa, Tomoaki Yoshino, Ko-Ichi Ito, Tatsuya Fukuda
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Crystals
• Subjects: thick b-SiC coating; chemical vapor deposition; punch and die system; dry, cold forging; galling-free forging; titanium
• Online Access: https://www.mdpi.com/2073-4352/10/6/539

A thick b-SiC CVD (chemical vapor deposition)-coated SiC device was developed as a new punch and die system for dry, cold forging of pure titanium and austenitic stainless-steel works. This b-SiC coating thickness was 4 mm, enough to make mechanical machining of a cavity into b-SiC coating core die. These b-SiC-coated punch and core dies were fixed into the cassette die for dry, cold forging experiments. The stainless steel and titanium wires with diameters of 1.0 mm were employed as the work material. Different from the conventional metallic and ceramic die systems suffering from work material transfer, this system sustained the galling-free cold, dry forging behavior up to a higher reduction of thickness than 30%. The power to stroke the relationship was in situ monitored to describe this forging behavior up to the specified reduction of the wires together with observations on the geometric change from a circular wire to a pentagonal prism bar. Precise scanning electron microscopy-electron-dispersive X-ray spectroscopy (SEM-EDX) analyses were performed to describe the material compatibility on the contact interface between b-SiC coating and elastoplastically deforming works.