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为研究Ni基Y2W3O12复合材料的热学性能,首先,采用二次焙烧法制备了负膨胀材料Y2W3O12;然后,将Y2W3O12与金属Ni进行混合,并在1 200℃、50 MPa的条件下热压烧结制得40vol%Y2W3O12/Ni复合材料;最后,对复合材料的成分及热膨胀性能进行了研究。结果表明:在热压烧结过程中,由于Ni的还原性比W差,相对于对比试样40vol%Y2W3O12/Cr复合材料中发生的复杂化学反应,40vol%Y2W3O12/Ni复合材料的两相之间并未发生反应,使40vol%Y2W3O12/Ni复合材料保持了较低的热膨胀系数;经数次循环退火释放热应力及去除Y2W3O12相的结晶水后,40vol%Y2W3O12/Ni复合材料在170~800℃温度范围内的热膨胀系数趋于稳定,约为3.4×10-6 K-1,与理论设计值4.0×10-6 K-1相近。
In order to study the thermal properties of Ni-based Y2W3O12 composites, firstly, the negative-expansion material Y2W3O12 was prepared by the secondary calcination method. Then, Y2W3O12 was mixed with metal Ni and hot-pressed at 1200 ℃ and 50 MPa Get 40vol% Y2W3O12 / Ni composites; Finally, the composition of the composite materials and thermal expansion properties were studied. The results show that, during the hot-press sintering process, the 40vol% Y2W3O12 / Ni composites have the same chemical composition as the 40vol% Y2W3O12 / Cr composites 40vol% Y2W3O12 / Ni composites maintained a low coefficient of thermal expansion. After several cycles of annealing to release thermal stress and remove the crystal water of Y2W3O12phase, The coefficient of thermal expansion tends to be stable in the temperature range of about 3.4 × 10-6 K-1, which is close to the theoretical design value of 4.0 × 10-6 K-1.