The reaction process of ZrC2ZrB 2 -based Cu cermets from the (1 ¹ x wt.%)(1B 4 C3Zr)x wt.%Cu system (Zr/B 4 C = 3 in molar ratio) was explored. Results showed that ZrC and ZrB 2 were mostly produced through the dissolution of B 4 C into a preformed ZrCu liquid. With an increase in x, the synthetic ZrC2ZrB 2 and generated heat were reduced. This effect decreased an ability for ZrCu liquid to propagate in the reactants, and restrained the dissolution Zr. As a result, the complete synthesis of ZrC2ZrB 2 failed in the systems with a higher Cu content (e.g., 50 wt.%). Furthermore, after the precipitation of ZrC and ZrB 2 , the liquid surrounding would prevent ZrC and ZrB 2 from growing. Increasing Cu content enhanced the amount of ZrCu melt. This behavior contributed to a decline in ZrC2ZrB 2 particle sizes, and the production of fine ceramic particles (³200 nm). It is also revealed that the formation of ZrC2ZrB 2 is a multistep process, which results in the inhomogeneity of ZrC2ZrB 2 particle sizes. A valuable approach was proposed to explore the relationship between reaction process and synthesized products of combustion synthesis-related technique.

Elastodynamic problems are investigated in this work by employing the enriched finite element method (EFEM) with various enrichment functions. By performing the dispersion analysis, it is confirmed that for elastodynamic analysis, the amount of numerical dispersion, which is closely related to the numerical error from the space domain discretization, can be suppressed to a very low level when quadric polynomial bases are employed to construct the local enrichment functions, while the amount of numerical dispersion from the EFEM with other types of enrichment functions (linear polynomial bases or first order of trigonometric functions) is relatively large. Consequently, the present EFEM with a quadric polynomial enrichment function shows more powerful capacities in elastodynamic analysis than the other considered numerical techniques. More importantly, the attractive monotonic convergence property can be broadly realized by the present approach with the typical two-step Bathe temporal discretization technique. Three representative numerical experiments are conducted in this work to verify the abilities of the present approach in elastodynamic analysis.

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