Naiming Lin

The development of fusion technology requires materials that can withstand heat, erosion, and activation at the edge of fusion plasma. Thanks to its high melting point, superior thermal conductivity, and excellent resistance to sputtering and retention, tungsten (W) has been regarded as the leading candidate for the plasma-facing materials (PFMs) of the main chambers and divertors in controlled thermonuclear fusion reactors. Nevertheless, W-PFMs are prone to complex severe surface deterioration under extreme service conditions during operation in fusion reactors. This includes physical/chemical sputtering, which results in material loss and plasma contamination; He-induced blistering and fuzz formation, which reduce thermal conductivity by several orders of magnitude; thermal fatigue cracking caused by transient loads; and neutron irradiation embrittlement, which leads to hardening, swelling, and loss of ductility. To overcome these issues while maintaining core thermophysical properties, protective surface layers have been fabricated primarily via chemical vapor deposition (CVD), physical vapor deposition (PVD), and spray and plasma-based surface modification technologies. This review assesses the recent progress in the fabrication of protective surface layers on W for PFM application in fusion reactors from a technical perspective, thereby offering new insights that advance the feasibility of fusion reactors and accelerating the practical realization of sustainable fusion energy systems.

The rocket sled slider is a key connection component between the rocket sled and the track for support, guidance and load-bearing, ensuring the system’s safe and reliable operation. Wear of sliders under high—velocity and heavy—load conditions is crucial for equipment reliability. This study establishes a wear prediction model for sled rails using ANSYS, incorporating a dimensionless acceleration factor into the simulation. By analyzing dynamic characteristics of contact friction stress, wear volume, depth, and stress over time, the tribological characteristics of 30CrMnSiNi2A steel sliders were studied. The simulation results showed that during dry—friction sliding, slider wear is highly related to speed and load, increasing significantly as they increase. The slider’s contact surface has non-uniform stress distribution with stress concentration and gradient changes. Quantitative analysis has revealed that friction stress is positively correlated with load, and its sensitivity to speed changes is high at low speeds and relatively low at high speeds.

Ti6Al4V (TC4) alloy, valued for its light weight, high strength, and excellent corrosion resistance, is widely used in aerospace, medical devices, chemical engineering, and marine applications. However, under severe service conditions, the material is subjected to the combined effects of tribocorrosion, leading to reduced service life. To enhance the tribocorrosion resistance of TC4 alloy in marine environments, a chromizing coating was fabricated on the TC4 surface by Double Glow Plasma Surface Alloying (DGPSA) technology. After maintaining at 800 ^∘ C for 3[ ]h, a chromizing coating with a thickness of 51.80[ ] [ ]m was successfully prepared. Following the plasma surface alloying treatment, the coating comprised Cr2Ti intermetallic compounds and solid solutions, resulting in an increase in microhardness from 332.65 HV0.1 to 637.29 HV0.1. Investigation of the tribological behavior of the alloy coating in simulated seawater revealed lower corrosion tendency and superior stability compared with the substrate. Under applied loads of 5[ ]N and 10[ ]N, the wear rates of the chromizing TC4 samples were [ ] [ ]mm[ ] and [ ], respectively, which are 42.9% and 45.8% lower than those of the substrate. These results demonstrate that the chromizing treatment effectively improves the tribocorrosion performance of TC4 alloy.