## 1 Introduction  
Due to the attractive characteristics of low density combined with high density, aluminum alloys have been used as structural materials in many industries, such as automobiles, aerospace, as well as drill pipe in extra-deep oil drilling [1; 2; 3; 4]. However, the deterioration in the mechanical properties of aluminum alloys at high temperature has largely restricted their usability in critical components [5; 6]. To overcome the limitations of the high-temperature mechanical properties of aluminum alloys, carbon materials (carbon fiber, carbon nanotube (CNT), graphene, etc.) reinforced aluminum matrix composites (AMCs) have been fabricated owing to their excellent properties such as high strength, high modulus, heat resistance and wear resistance [7; 8; 9; 10; 11]. The main problems limiting the application of carbon materials reinforced AMCs are concluded as the poor wettability and in situ chemical reaction between carbon materials and aluminum matrix. Due to non-wetting conditions between monolithic phases, it is difficult to fabricate carbon materials reinforced AMCs with high mechanical properties using traditional casting technologies [12]. To overcome this issue, researchers have proposed various modified processing methods, such as squeeze casting [13; 14], liquid infiltration [15; 16; 17] and powder metallurgy [18; 19; 20; 21]. On the other hand,the interfacial reaction plays a critical role in the mechanical properties of composites. Due to the low Gibbs free energy of the chemical reaction between aluminum and carbon, aluminum carbide (Al4C3) is formed at a temperature above 773 K [12; 22]. The formation of Al4C3 has been widely observed in CNTs/Al [23; 24], graphene/Al [25; 26] and carbon fiber/Al composites [27; 28]. However, the effects of Al4C3 on interfacial bonding and mechanical properties are still under debate. Some researchers claimed that the formation of brittle Al4C3 is detrimental to the mechanical properties of carbon materials/Al composites [29; 30; 31]. [PERSON] et al. [31] found that the tensile strength of T700 carbon fiber/Al composite decreased by 49% compared to that of M40 carbon fiber/Al composite due to the formation of coarsened Al4C3. In contrast, other researchers found that the Al4C3 formation is desirable for improving the interfacial bonding and solving the un-wetting condition [22; 32; 33; 34]. [PERSON] et al. [22] found that nanosized Al4C3 was beneficial for increasing the interface shear stress and improving the strength of composites, while micro-scale Al4C3, which was enlarged at high temperature, deteriorated the mechanical properties. For carbon fiber reinforced metal matrix composites, the addition of carbon fiber could largely change the fracture behavior of composites. Due to the low plasticity of carbon fiber, the elongation for carbon fiber metal matrix composites displayed a significant decrease. On the fracture surface of composites, carbon fiber was usually observed to be damaged in three modes, i.e., fiber pulled-out, debonding and fiber fracture [35], which was determined by the interface bonding between carbon fiber and matrix. The weak interface bonding strength led to the propagation of cracks along the interface, and finally, carbon fiber was pulled out or debonded from the matrix. On the other hand, when the tip stress of crack was lower than the interface bonding strength, carbon fiber tended to be sheared fractured. So far, many researchers have studied the fracture behavior of carbon fiber reinforced metal matrix composites at room temperature. For example, [PERSON] [28] found that cracks in continuous carbon fiber/2014 Al were mainly generated in the matrix and the strong interface bonding caused shearing of fibers. It is known that temperature played a critical role in affecting the interfacial microstructure of composites. Thus, the fracture behavior of composites might be different at high temperatures.