Ni-P-Ti composite coatings have been prepared by co-depositing Ni-P and nano-Ti particles which were then annealed. Tensile tests were conducted on standalone coatings to acquire the mechanical properties of the coatings without the effect of the steel substrate. The Hertzian indentation tests were performed on coating-steel substrate bilayer systems to investigate the indentation behavior of the coatings. After annealing, Ni₃Ti and superelastic NiTi phases are identified in composite coatings by XRD and EDS. Compared to the as-deposited Ni-P coatings, the toughness of the annealed composite coatings improved significantly. The superelastic effect of NiTi particles was observed in the Hertzian indentation behavior of the annealed composite coatings. The strengthening mechanisms as well as toughening mechanisms such as crack bridging, crack deflection, crack arresting, and transformation toughening were discussed. Recovery ratio (η) values as well as Hertzian indentation stress distribution were computed to analyze and explain the indentation behavior of the as-deposited and annealed coatings.

通过共沉积Ni-P和纳米Ti颗粒，然后对其进行退火，可以制备Ni-P-Ti复合涂层。在独立的涂层上进行拉伸测试，以获取涂层的机械性能，而不受钢基材的影响。在涂层-钢基材双层系统上进行了赫兹压痕测试，以研究涂层的压痕行为。退火后，Ni ₃XRD和EDS在复合涂层中鉴定出Ti相和超弹性NiTi相。与沉积后的Ni-P涂层相比，退火后的复合涂层的韧性明显提高。在退火的复合涂层的赫兹压痕行为中观察到NiTi颗粒的超弹性效应。讨论了强化机制和增韧机制，如裂纹桥接，裂纹挠度，止裂和相变增韧。计算回收率（η）值以及赫兹压痕应力分布，以分析和解释沉积和退火涂层的压痕行为。