This thesis is focused on the high temperature deformation behavior and microstructural evolution during hot working process of 2124Al alloy and 20vol% SiCp/2124Al composite. Flow curves, microstructures of 2124Al alloy and 20vol% SiCp/2124Al composite were analyzed to optimize the hot working process conditions. Billets of 2124Al alloy and 20vol% SiCp/2124Al composite were fabricated by hot pressing process under a pressure of 90MPa at 570℃ for 10min. under $1×10^{-5}$torr. The average grain sizes of billets were 17㎛ for 2124Al and 20㎛ for 20vol% SiCp/2124Al. The high temperature deformation behavior of 2124Al alloy and 20vol% SiCp/2124Al composite have been investigated by isothermal compressive tests at temperatures ranged 400-475℃ with constant strain rates ranged $10^{-3}-1 s^{-1}$. The stress-strain curve during high temperature deformation exhibited a peak stress, then the flow stress decreased gradually into a steady state stress with increasing the strain. The peak stress of 2124Al and SiCp/2124Al increased with decreasing the temperature and with increasing the strain rate. The flow softening behavior after the peak stress is attributed to the dynamic recrystallization(DRX) of 2124Al alloy. The dependence of flow stress on temperature and strain rate could be formulated well by a hyperbolic-sine relationship using the Zener-Hollomon parameter. The activation energies were calculated as 181kJ/mol for 2124Al alloy and 212kJ/mol for 20vol% SiCp/2124Al composite. Using the normalized Zener-Hollomon parameter(Z/A) and the effective stress on matrix based on the load transfer analysis, the flow stress of 20vol% SiCp/2124Al composite is similar to that of 2124Al alloy. If the flow stress of 2124Al alloy is known, the effective flow stress on matrix of 20vol% SiCp/2124Al composite can be predicted from a normalized hyperbolic-sine relationship. The degree of flow softening increased with increasing the strain rate and with decreasing the temperature. In low strain rate region below $10^{-2} s^{-1}$, the elongated and equiaxed grains were observed due to the occurring of dynamic recovery(DRV) and dynamic recrystallization(DRX) at the same time. In high strain rate region above $10^{-1} s^{-1}$, only equiaxed grains were observed due to the occurring of dynamic recrystallization(DRX). It is possible to analyze the microstructural evolution during the hot extrusion process from the results of hot compression test. The elongated and equiaxed grains were observed at a lower extrusion ratio of 25:1 due to the occurring of dynamic recovery(DRV) and dynamic recrystallization(DRX) at the same time. The equiaxed grains were observed at a higher extrusion ratio of 70:1 due to the occurring of dynamic recrystallization(DRX) only.
