Scholarlink

<p>To enhance the tensile strength and corrosion resistance of critical components in high-pressure cam pumps for high-speed heavy-duty equipment, this study employed ZG42CrMoA alloy steel as the substrate. Utilising CO<sub>2</sub> laser technology, a four-axis CNC machine, and a gas-assisted coaxial powder delivery system, a Ni45 coating was fabricated. We incorporated pure Y with varying concentrations of 0.0, 0.3, 0.6, and 0.9&#xa0;wt.%. Characterisation analyses were conducted using scanning electron microscopy, x-ray diffraction, universal tensile testing machines, and electrochemical testing. The results indicate that the addition of pure Y did not alter the phase composition of the Ni45 coating, which remained composed of <i>γ</i>-Ni, M<sub>23</sub>C<sub>6</sub> and Ni<sub>3</sub>B phases. However, microstructural optimisation was achieved through heterogeneous nucleation and melt pool control. The addition of pure Y caused the coating’s tensile strength to exhibit a trend of an initial increase followed by decrease. At a pure Y content of 0.6 wt.%, the coating’s tensile strength reached a maximum value of 722.96 MPa, representing an 11.01% improvement over the Ni45 coating (651.26 MPa) and demonstrating superior tensile properties. This enhancement stems from pure Y’s significant grain refinement within the coating, increasing both total grain boundary area and the proportion of high-angle grain boundaries. This raises the fracture energy required, thereby reducing stress concentration points. Electrochemical corrosion test results indicate that the addition of pure Y effectively reduces the corrosion current density of the coating. The 0.6 wt.% pure Y addition group exhibited the lowest corrosion current density at merely 7.14<i> μ</i>A/cm<sup>2</sup>, representing a 32.51% reduction compared to the pure Ni45 coating. This mechanism stems from Y-induced grain refinement promoting the formation of a uniform passivation film However, excessive pure Y ( ≥ 0.9 wt.%) leads to grain boundary enrichment and exacerbated chromium segregation, resulting in a slight decrease in corrosion resistance.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Effect of Y Concentration on the Microstructural Evolution and Mechanical Properties of Laser-Clad Ni45 Coatings

  • 期刊论文

  • 发表日期：

    2026年7月14日

查看全文
  • Yunfeng Li,
  • Jiaqi Zhang,
  • Yan Shi,
  • Guangjun Jiang,
  • Cong Ni

摘要

To enhance the tensile strength and corrosion resistance of critical components in high-pressure cam pumps for high-speed heavy-duty equipment, this study employed ZG42CrMoA alloy steel as the substrate. Utilising CO2 laser technology, a four-axis CNC machine, and a gas-assisted coaxial powder delivery system, a Ni45 coating was fabricated. We incorporated pure Y with varying concentrations of 0.0, 0.3, 0.6, and 0.9 wt.%. Characterisation analyses were conducted using scanning electron microscopy, x-ray diffraction, universal tensile testing machines, and electrochemical testing. The results indicate that the addition of pure Y did not alter the phase composition of the Ni45 coating, which remained composed of γ-Ni, M23C6 and Ni3B phases. However, microstructural optimisation was achieved through heterogeneous nucleation and melt pool control. The addition of pure Y caused the coating’s tensile strength to exhibit a trend of an initial increase followed by decrease. At a pure Y content of 0.6 wt.%, the coating’s tensile strength reached a maximum value of 722.96 MPa, representing an 11.01% improvement over the Ni45 coating (651.26 MPa) and demonstrating superior tensile properties. This enhancement stems from pure Y’s significant grain refinement within the coating, increasing both total grain boundary area and the proportion of high-angle grain boundaries. This raises the fracture energy required, thereby reducing stress concentration points. Electrochemical corrosion test results indicate that the addition of pure Y effectively reduces the corrosion current density of the coating. The 0.6 wt.% pure Y addition group exhibited the lowest corrosion current density at merely 7.14 μA/cm2, representing a 32.51% reduction compared to the pure Ni45 coating. This mechanism stems from Y-induced grain refinement promoting the formation of a uniform passivation film However, excessive pure Y ( ≥ 0.9 wt.%) leads to grain boundary enrichment and exacerbated chromium segregation, resulting in a slight decrease in corrosion resistance.