Composites With Low CTE And High TC Used For Electronic Packaging--The Investigation On The Preparation And Properties Of NTE ZrV₂O₇ And ZrV₂O₇/Al Composite Materials

In this paper, ZrV2O7 with negative-thermal-expansion(NTE) was prepared and studied by two different synthetic routes-directly-calcined synthesis from oxides and calcined synthesis with the precursor prepared by wet-chemical technique. And the mechanism of preparation was carefully studied by XRD, SEM, and Dilatometer ,it indicated that the samples by the former method are to obtained single phase ZrV2O7 because their synthesis belong to solid-state reactions which needs oxides ZrO2 and V2O5 to be closely touched each other; however, the synthesis by the latter method are easy to take place because ZrV2O7 is achieved by in-situ thermal decomposition and synthesis of the precursor whose powder particle can be nanometer scale (less than 100nm) .Therefore, the product by wet-chemical technique is highly-pure ZrV2O7 phase and shows remarkable negative thermal expansion characteristic beyond 400K .Based on the work above, further research was to taken to study the interface behaviors and thermal expansion character of composite ZrV2O7 /Al of which ZrV2O7 was obtained by calcined synthesis with the precursor prepared by wet-chemicaltechnique. Through powdermetallurgy, ZrV2O7 and Al composites according to different formation-sintering techniques. The results of XRD, SEM and EPS display that all ZrV2O7 /Al composites have good sintering and dipping characteristics in certain scopes of sintering temperature. No matter whether they are in solid state or melting state. But the more reactive Al can replace the Zr4+ ions in ZrV2O7 and cause the formation of AlVO3 and AlVO4 or metal Al may penetrate into ZrV2O7 and form Zr1-xAlxV2O7-y composites during the sintering process. The reaction degree will increase with the increase of sintering temperature. The results of Dilatometer demonstrates that ZrV2O7 /Al composites have much lower thermal expansion coefficient than metal Al, though it is still positive.