Study On Ablation Resistance Of Marine Titanium Alloys And Chromium Coatings After Processing

In the manufacture and maintenance of marine vessels, marine components are subjected to extreme operating environments, especially the challenge of high-temperature ablation, which greatly limits their service life. This paper focuses on an innovative processing method aimed at enhancing the ablation resistance of titanium alloy materials by treating them with a chromium layer on their surface through a specific process. Through laser ablation experiments that simulate the actual operating environment of a ship, we provide insights into the effects of this processing treatment on the properties of titanium alloys and chrome coatings.
With the continuous progress of marine engineering technology, the performance requirements for ship components are becoming increasingly stringent. Titanium alloy, with its excellent mechanical properties and corrosion resistance, occupies an important position in shipbuilding. However, high-temperature ablation in the marine environment is still a major challenge that restricts its application. In order to meet this challenge, we have adopted advanced processing technology to surface treat titanium alloys with chromium plating, with a view to enhancing their ablative corrosion resistance.

Processing method and material preparation
Processing of titanium alloy substrate: the titanium alloy raw material was cut into specimens of standard size (2 cm × 1 cm × 0.5 cm) using precision wire-cutting technology. Subsequently, 1500 grit sandpaper was used for polishing, then abrasive paste was used to polish to a mirror effect, and finally ultrasonic cleaning was used to remove surface impurities to ensure the surface finish of the substrate.
Chromium Coating Processing: Chromium coatings were deposited on the surface of the prepared titanium alloy samples using advanced arc ion plating technology. By precisely controlling the vacuum (6×10^-3 Pa), temperature (300 °C), NH3 pressure (2~3 Pa) and bias voltage (800~1000 V), the chromium coating is ensured to be uniform and dense, and the deposition time is controlled at 10~20 minutes.
Laser ablation experiment and result analysis
A series of laser ablation experiments were designed to evaluate the ablation resistance of the processed titanium alloy and chromium coating. The experiments used a homemade long pulse width laser (model FLK-TIX6409Hz) to simulate the ablation process of ship parts in a high temperature environment by adjusting the pulse energy and the number of pulses.
The experimental results show that the untreated titanium alloy substrate has large and deep ablation craters on the surface under laser ablation, with a large number of cracks in the center area although smooth, and a thick oxide accumulation in the edge area. In contrast, the chromium-plated layer on the surface of the processed titanium alloy showed superior ablation resistance under the same conditions, with shallower ablation pits and fewer cracks, and significantly less oxide buildup.
Through scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDAX) micro-morphology and compositional analysis of the ablated surfaces, we found that the chromium coating effectively blocked the direct erosion of high-temperature oxygen on the titanium alloy substrate and reduced the occurrence of oxidation reactions, thus improving the overall ablation-resistant properties of the material.
Conclusion and Outlook
In this study, the ablation resistance of titanium alloys and chromium coatings was successfully enhanced through innovative processing methods. The experimental results show that the chromium coating plays an important role in protecting the titanium alloy substrate from high-temperature ablation, which significantly extends the service life of the ship components. Future research can further explore the effects of different processing parameters on the coating performance, as well as the development of more high-performance protective coating materials, in order to meet the urgent demand for high-performance parts in the field of shipbuilding.