본문 바로가기
  • Home
Basic Search

Effects of spray distance and gun traverse speed on the microstructure and mechanical properties of WC-Co-Cr coatings deposited by High-Velocity Oxygen Fuel (HVOF) spraying

  • Journal of the Korean Crystal Growth and Crystal Technology
  • Abbr : J. Korean Cryst. Growth Cryst. Technol.
  • 2026, 36(1), pp.36~49
  • DOI : 10.6111/JKCGCT.2026.36.1.036
  • Publisher : The Korea Association Of Crystal Growth, Inc.
  • Research Area : Engineering > Materials Science and Engineering
  • Received : December 5, 2025
  • Accepted : January 14, 2026
  • Published : March 31, 2026

Sang-In Kim 1,  TaeHyeon Kim 2,  Su-Han Bae 1,  Chang-Hun Hwang 3,  Jong-Ho Kong 3,  Jeong-Hong Lee 3,  Kim Se-Yun 4

1경남대학교
2경남대학교 대학원 메카트로닉스공학과
3(주)에어로코텍
4경남대학교 미래자동차공학과

Accredited

ABSTRACT

This study investigates the effects of spray distance (250, 300, and 350 mm) and gun traverse speed (4, 7, and 10 mm/s) in the High Velocity Oxygen Fuel (HVOF) process on the microstructural, crystallographic, and mechanical properties of WC-10Co-4Cr coatings. The WC-Co-Cr feedstock powder consists of agglomerated 1~2 µm primary particles, which inherently promotes the formation of partially molten and unmelted particles during spraying due to heterogeneous internal and external melting behavior. When the spray distance was reduced to 250 mm at a gun traverse speed of 7 mm/ s, the shortened particle flight time resulted in insufficient melting, leading to an increased fraction of unmelted particles and interfacial delamination (9.48 %). As a consequence, poor inter-splat bonding caused a reduction in Almen/bending thickness (90 µm) and an increase in residual stress (0.35 mm). In contrast, at a spray distance of 350 mm, the extended flight time increased particle exposure to oxygen, resulting in a higher defect content (0.872 %). Despite this, stabilization of the jet flow improved particle impact angle and lamellar stacking, yielding the highest bonding strength (77.3 MPa) and hardness (1,400 Hv). Variations in gun traverse speed significantly altered the surface thermal history and splat solidification behavior. Compared with the reference condition (300 mm, 7 mm/s), both slower (4 mm/s) and faster (10 mm/s) traverse speeds produced denser lamellar structures and enhanced splat continuity. At 4 mm/s, localized re-melting and increased binder fluidity reduced porosity but slightly degraded bonding strength due to excessive thermal input. Conversely, at 10 mm/s, suppressed surface overheating and reduced particle scattering led to a more uniform splat structure, accompanied by a slight increase in W2C relative peak intensity and improved bonding strength (74.1 MPa). Overall, spray distance and gun traverse speed are critical parameters governing particle melting, cooling, flight stability, and binder continuity, which collectively determine splat morphology, defect distribution, decarburization behavior, and mechanical performance of WC-Co-Cr coatings.

Statistics

  • 28 Viewed
  • 21 Downloaded

Tools

Issue List

Citation status

* References for papers published after 2024 are currently being built.

Basic Search Advanced Search