The effect of carbon fiber length on the thermal expansion of fiber‐reinforced particulate hybrid composites

Thermal expansion of materials is a critical factor influencing their dimensional stability. This study explores the regulation of thermal expansion in composite materials through the incorporation of carbon fibers and zirconium tungstate particles. The influence of fiber length on the thermal expansion behavior of these composites was investigated. The investigation reveal that the variation in the relative elongation ratio (dl/L0) of the carbon fiber‐reinforced zirconium tungstate composites is nonlinear, characterized by an initial increase, subsequent decrease, and a final resurgence. Notably, an increase in fiber length results in a mitigated rate of increase in the (dl/L0) ratio. Furthermore, composites fabricated with shorter fibers exhibit a higher coefficient of thermal expansion (CTE). Upon elevating the temperature to 250°C, the CTE for composites reinforced with 100 and 500 mesh carbon fibers escalate to 24.5 × 10−6/K and 74.6 × 10−6/K, respectively. These values represent an 8% and 116% enhancement relative to those measured at 50°C.Highlights The thermal expansion properties are improved by adding carbon fiber and ZrW2O8 nanoparticles. Utilizing fiber lengths ranging from 100 to 500 mesh effectively diminishes the CTE. The Cf‐ZrW2O8/9621 composite exhibits non‐linear behavior in its dl/L0 ratio. Within the range, longer fibers are more beneficial for reducing the CTE.