Spark plasma sintering (SPS) is a widely used technique for sintering thermoelectric devices. In this process, the heat generated by Joule heating is primarily transferred to the die surface through radiative heat transfer, causing temperature non-uniformity within the specimen. These discrepancies in temperature distribution cause localized changes in the properties of the thermoelectric device, which presents significant engineering challenges in managing heat transfer during the sintering process. This study proposes a thermal design approach to reduce the temperature gradient within the specimen in the existing SPS device. The idea of the auxiliary heating system was evaluated using numerical simulation validated with experimental comparison. Design variables, heating power (an operating parameter) and heater depth (a geometric parameter), were chosen to balance the amount of Joule heating to the heat produced by the auxiliary heating system. The optimization process with sensitivity analysis led to the selection of an auxiliary heating system capable of reducing the temperature gradient within 61.1 K/m. This achievement allows for the sintering of thermoelectric devices with enhanced thermoelectric performance.

中文翻译：

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提高放电等离子烧结装置温度均匀性的热设计


放电等离子烧结（SPS）是一种广泛使用的热电器件烧结技术。在此过程中，焦耳热产生的热量主要通过辐射传热传递到模具表面，导致试样内温度不均匀。这些温度分布的差异会导致热电装置性能的局部变化，这对烧结过程中的传热管理提出了重大的工程挑战。本研究提出了一种热设计方法来降低现有 SPS 装置中样品内的温度梯度。通过数值模拟和实验比较验证了辅助加热系统的想法。选择设计变量、加热功率（操作参数）和加热器深度（几何参数）来平衡焦耳加热量与辅助加热系统产生的热量。通过灵敏度分析的优化过程，最终选择了能够将温度梯度降低到 61.1 K/m 以内的辅助加热系统。这一成就使得能够烧结具有增强热电性能的热电器件。