Abstract The Abrasive Jet Machining (AJM) of Polydimethylsiloxane (PDMS) is very slow or even impossible at room temperature due to its ability to absorb the energy of the impacting particles. Cryogenic Abrasive Jet Micromachining (CAJM) can enhance the material removal rate, and accordingly, the mechanical performance of PDMS can critically affect its processability. The goal of this study is to investigate the physical properties of PDMS at different temperatures. For this, PDMS samples were fabricated for compressive, hardness, X-ray Diffraction and linear expansion coefficient testing, according to GB standards. The results showed the following values: compressive modulus of 17.31–1160.1 MPa; ultimate compressive strength of 160.25–224.50 MPa; hardness of 43 ShA–90.67 ShD, coefficient of thermal expansion (CTE) of 247E-06 1/K (103 K to RT, 3 K/min) at different temperatures, over the range of room temperature at, RT = 298 to 123 K. Moreover, the influence of temperature on the compressive fraction surface microstructure was analyzed with scanning electron microscopy (SEM). The results showed that with the decrease of temperature, the failure mode of PDMS material changed from ductile to brittle, and the material exhibited evident brittle characteristics until 123 K.

中文翻译：

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聚二甲基硅氧烷（PDMS）不同温度力学性能的实验研究

摘要 聚二甲基硅氧烷 (PDMS) 的磨料喷射加工 (AJM) 在室温下非常缓慢甚至不可能，因为它能够吸收撞击颗粒的能量。低温磨料射流微加工 (CAJM) 可以提高材料去除率，因此，PDMS 的机械性能会严重影响其可加工性。本研究的目的是研究 PDMS 在不同温度下的物理特性。为此，根据 GB 标准制作了 PDMS 样品用于压缩、硬度、X 射线衍射和线性膨胀系数测试。结果显示以下值： 压缩模量 17.31–1160.1 MPa；极限抗压强度160.25-224.50 MPa；硬度为 43 ShA–90.67 ShD，热膨胀系数 (CTE) 为 247E-06 1/K（103 K 至 RT，3 K/min) 在不同温度下，在室温范围内，RT = 298 至 123 K。此外，使用扫描电子显微镜 (SEM) 分析温度对压缩分数表面微观结构的影响。结果表明，随着温度的降低，PDMS材料的破坏模式由韧性转变为脆性，材料在123 K之前表现出明显的脆性特征。