Method for preparing near-zero thermal expansion composite material

Abstract

The invention provides a near-zero thermal expansion composite material and a preparation method thereof. The preparation method comprises the following steps of: (a), mixing flux powder and tungstate solid solution precursor powder to obtain a first mixture, wherein the tungstate solid solution precursor has a chemical formula shown as the general formula (I) as follows: Zr(W1-yMoy)2-xVxO8-x / 2(OH)2(H2O)2(I), in the general formula (I), x is more than or equal to 0 and less than or equal to 0.4, and y is more than or equal to 0 and less than 1; and the flux comprises PbO, B2O3 and SiO2; (b), pressing and forming the first mixture to obtain a formed body; and (c), roasting the formed body to obtain the near-zero thermal expansion composite material. In the invention, the near-zero thermal expansion composite material is prepared by mixing and roasting the flux comprising PbO, B2O3 and SiO2 and the tungstate solid solution precursor. Experimental results show that the thermal expansion coefficient of the near-zero thermal expansion composite material prepared by the preparation method disclosed by the invention in a temperature range of minus 50 to plus 300 degrees centigrade is in a range of + / - 2*10<-6>K<-1>.

Description

technical field [0001] The invention relates to the field of composite materials, in particular to a method for preparing a near-zero thermal expansion composite material and the near-zero thermal expansion composite material. Background technique [0002] The near-zero thermal expansion composite material mentioned in this article refers to an extremely low thermal expansion material with a very low thermal expansion coefficient or a thermal expansion coefficient ≤±2×10 -6 K -1 Near-zero thermal expansion materials, near-zero thermal expansion composite materials have good thermal shock resistance, and have always been one of the hotspots in the field of materials science. Near-zero expansion composites have broad application prospects in many fields. For example, when a near-zero thermal expansion material is used as a coating on the surface of a high-precision optical mirror, the problem of optical performance degradation due to temperature changes can be prevented. As...

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Problems solved by technology

In the prior art, the published ZrW 2 o 8 Based thermally expandable composites with metal matrix - cubic ZrW 2 o 8 Composite materials, specific examples such as Cu-ZrW 2 o 8 , but due to Cu and ZrW 2 o 8 The expansion coefficient does not match, it is easy to generate strong thermal stress, which induces ZrW 2 o 8 Phase transformation occurs into γ phase, resulting in a higher coefficient of thermal expansion of the composite material, thereby limiting the application of the composite material (H.Holzer, D.C.Dunand.Phase transformation and thermal expansion of Cu / ZrW 2 o 8 metal matrix composites. J Mater Res. 1999, 14: 780-789)

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