Modeling supply risk propagation in tungsten industry chain: A multi-layer network framework with inter-layer...

Tungsten, due to its high melting point, high density, and wear resistance, is irreplaceable in critical fields such as aerospace and defense. However, with the continued global growth in tungsten demand, its geographical monopoly and the technological oligopoly within the industry make local supply disruptions prone to triggering systemic risks through trade and production linkages. Therefore, it is crucial to investigate the effects and patterns of risk propagation caused by supply shocks in core economies. This study constructs a tungsten industry chain multi-layer network (TICMN) based on the 2022 global trade data for tungsten industry chain products at various links. By integrating the coupled PageRank (CPR) algorithm with a cascading failure model, we simulate the risk propagation process of key risk sources. The findings reveal several key insights. First, country centralities across different layers of the industry chain vary significantly under different feedback strengths. Second, the response of inter-layer propagation to impact strength is more sensitive compared to intra-layer transmission. Third, the ability of different countries to trigger systemic cascades as risk sources is not solely determined by their centrality but is also closely related to the functional roles they play within the industry chain. Finally, China exhibits a "full-chain penetration" role throughout the propagation process, while Australia is more likely to trigger global impacts via cross-layer propagation. These findings are of great significance for policymakers in formulating targeted mitigation strategies and ensuring the security of resource supply.