This Paper investigates the role of microcracks in Hall thruster wall erosion. The formation and growth of microcracks on the surface of M26 grade boron nitride composite due to repeated thermal shock was quantified, and the subsequent impact of microcracks on plasma erosion was assessed. Thermal shock cycles (20 → 800 → 20°C) were provided by a radiation oven to induce thermal stresses similar to those incurred by a Hall thruster wall. The average ratio of crack area to total area was observed to grow as a power law with subunity exponential from 4–5% before thermal cycling to 15–18% after 20 thermal shock cycles. Cycled and control samples were simultaneously exposed to argon plasma with average ion energy of 130 eV. All samples were observed to preferentially retain boron nitride relative to silica, and microcracks were not observed to significantly impact surface composition or feature development.

本文研究了微裂纹在霍尔推进器壁腐蚀中的作用。量化了由于反复热冲击而在M26级氮化硼复合材料表面形成的微裂纹，并评估了微裂纹对等离子体腐蚀的后续影响。辐射烤箱提供了热冲击循环（20→800→20°C），以引起类似于霍尔推力器壁所产生的热应力。观察到裂纹面积与总面积的平均比率随着幂律的增长而增长，次幂指数从热循环前的4–5％增至20个热冲击循环后的15–18％。循环样品和对照样品同时暴露于平均离子能量为130 eV的氩气等离子体中。观察到所有样品相对于二氧化硅优先保留氮化硼，