Effect of Cryogenic Treatment of Tungsten Carbide Tools for Die Application

EasyChair Preprint 2760

Abstract

This study investigated effects of cryogenic treatment and post tempering on microstructure parameters and mechanical properties of cemented tungsten carbide for die applications.  Carbide grain size was increased after the cryogenic treatment resulted in an increased carbide contiguity.  After tempering process, tungsten carbide grain size was reduced and more uniform in size distribution with less in WC-Co debonding.  The fracture toughness of cryogenically treated carbide which evaluated from microstructure parameter was slightly increased from 20 to 21.1 MPa∙m1/2 .  After tempering, the fracture toughness was almost unchanged compared to that of untreated sample and the number of tempering cycles did not affect the fracture toughness.  However, hardness and scratch resistance were improved 10% and 60%, respectively, by cryogenic treatment.  Increasing the number of post tempering cycles after applying the cryogenic treatment result in reducing hardness but did not affected the scratch resistance of the cemented tungsten carbide.  In addition, results of ball on disc tribological testing indicated that wear resistance of the cemented tungsten carbide could be improved by cryogenic treatment due to the higher hardness and scratch resistance as expected.   The wear volume was increased with the number of tempering cycles. Therefore, sliding wear resistance and scratch resistance applications in which material surface failure behavior is mainly controlled by surface hardness, post tempering process might not be required.

Keyphrases: Cryogenic treatment, Fracture toughness, cemented tungsten carbide, post tempering, wear resistance

@booklet{EasyChair:2760,
  author    = {Chayamas Yooliengpun and Nawatud Bandasak and Karuna Tuchinda and Onnjira Diewwanit},
  title     = {Effect of Cryogenic Treatment of Tungsten Carbide Tools for Die Application},
  howpublished = {EasyChair Preprint 2760},
  year      = {EasyChair, 2020}}