In this study, NiAl coating was produced on 304 stainless steel material using High velocity oxygen-fuel (HVOF) spray technique. The influence of oxygen flowrate on the microstructure, porosity and hardness of the coating was investigated. Further, the mechanical properties of HVOF sprayed samples were determined at various temperatures using optical, laser excitation with interferometer reception, completely non-contact and nondestructive based laser ultrasound technique. The outcomes of this study indicate that the microstructure and properties of the coatings are sensitive to the oxygen flowrate. A coating with highest hardness and less porosity was achieved while increasing the oxygen content. Higher Young's modulus was observed at 20 °C and gradually decreases with the rise in temperature. The behavior of Young's modulus and Poisson's ratio at elevated temperature indicates that originate from the existence of a gas flow rate in the NiAl coating, leading to reduced flexural strength with increased temperature. Both inversion and experimentation result shows a good agreement in elastic properties of HVOF coated sample. The proposed laser ultrasound technique is valid for remote, noncontact and nondestructive characterization of the Young's modulus and Poisson's ratio of the coatings in elevated temperature environments.

在这项研究中，使用高速氧燃料（HVOF）喷涂技术在304不锈钢材料上制备了NiAl涂层。研究了氧气流量对涂层微观结构，孔隙率和硬度的影响。此外，使用光学，干涉仪接收的激光激发，完全基于非接触和非破坏性的激光超声技术，在各种温度下确定了HVOF喷涂样品的机械性能。这项研究的结果表明，涂​​层的微观结构和性能对氧气流量敏感。在增加氧气含量的同时，获得了具有最高硬度和较低孔隙率的涂层。在20℃下观察到较高的杨氏模量，并随温度升高而逐渐降低。杨的行为 s模量和高温下的泊松比表明，NiAl涂层中存在气体流速，导致随温度升高而降低的弯曲强度。反演和实验结果均表明HVOF涂层样品的弹性具有良好的一致性。所提出的激光超声技术对于在高温环境下涂层的杨氏模量和泊松比的远程，非接触和非破坏性表征是有效的。