Abstract

Densely consolidated WC-based hard materials with 5–20 vol% ZrSiO₄ was fabricated by spark plasma sintering at 1400 ℃ at a constant heating rate of 70 ℃/min⁻¹. To achieve mechanical alloying of WC-ZrSiO₄, planetary ball milling was carried out for 12 h, during which the brittle-brittle components (WC-ZrSiO₄) became fragmented and their particles became refined. It was observed that certain, specific, non-isothermal sintering kinetics, such as apparent activation energy, sintering exponents, and densification strain, affected the densification behavior. The evolution of phase structure from powder to compact was found to be related the lattice distortion and micro-strain in the basal planes of WC. By examining the mechanical properties of the samples, it was that the added zircon content leads to enhanced fracture toughness (12.9 MPa m^1/2) owing to the presence of WC-ZrSiO₄ in the cemented carbide. In fact, the microcrack propagation of the fracture passed through zircon from a transgranular to a ductile component (fcc) where the crack tips could be absorbed.

Graphic Abstract

中文翻译：

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通过火花等离子体烧结快速固化 WC-ZrSiO4 硬质材料：微观结构、致密化和机械性能

摘要

通过在 1400 ℃下以 70 ℃/min ^-1的恒定加热速率进行放电等离子烧结，制备了具有 5 – 20 vol% ZrSiO _{4 的}致密固结的 WC 基硬质材料。为了实现 WC-ZrSiO _{4 的}机械合金化，行星球磨进行了 12 h，在此期间，脆脆组分（WC-ZrSiO ₄）变得支离破碎，它们的颗粒变得细化。据观察，某些特定的、非等温的烧结动力学，如表观活化能、烧结指数和致密化应变，会影响致密化行为。发现相结构从粉末到压块的演变与 WC 基面的晶格畸变和微应变有关。通过检查样品的机械性能，由于硬质合金中 WC-ZrSiO ₄的存在，添加的锆石含量导致断裂韧性提高（12.9 MPa m ^1/2）。事实上，裂缝的微裂纹扩展通过锆石从穿晶到可吸收裂纹尖端的延性组件 (fcc)。

图形摘要