The capability to fabricate ultra-low and customizable CTE materials with good mechanical properties in a simple method was demonstrated in this work. For this purpose, nano beta-eucryptite and alumina powders were synthesized and used in the composite's fabrication. Four composites of alumina and a second-phase beta-eucryptite were prepared, containing 10, 20, 30, and 40 wt.% beta-eucryptite. The temperature effect on prepared composites is investigated. The results of XRD analysis and the microstructures of prepared composites are discussed with results of mechanical strength and thermal expansion at temperature ranges of 1400, 1500, and 1550 °C. The CTE of alumina-beta-eucryptite composites decrease as the beta-eucryptite content increases, reaching -1.036 × 10–6 °C−1. The findings show that a composite with a very low thermal expansion coefficient and good mechanical properties can be designed and used in different applications. [ABSTRACT FROM AUTHOR]