Studies On Elastic Modulus, Internal-friction And Processing Of 6066Al/SiC_p Composites

In this thesis, 6066Al/SiC_p composites have been studied with regard to the elastic modulus, internal-friction , characteristic of interface between Al and SiC_p, heat-treatment parameters and fracture mechanism . Furthermore , flow-stress equations of 6066Al/SiC_p at high temperature(℃) were created by hot compression, parameters of 6066Al/SiC_p composites such as extrusion force, extrusion rate in extrusion processing were gotten by numerical simulation. Some meaningful results are therefore found as followings.1. Young's modulus of 6066Al/SiC_p (E_C) is proportional to the SiC_p volume φ ( % )(when φ%< 40% in this experiment). The relations can be expressed as: For Powder metallurgy (PM) 6066Al/SiC_p, E_C(GPa) = 69.8 + 1.795φ For Sprayed deposition (SD) 6066Al/SiC_p, E_C(GPa) = 69.8 + 1.402φGenerally, E_C can be expressed as E_C(J) = , in which J is a structurefactor. When a suitable J factor is chosen, the calculated E_C results are close to the measured E_C value. For 6066Al/SiC_p, J is equal to 0.1.2. The internal-friction of 6066Al/SiC_p and 6066A1 increase as the increasing of frequency and temperature. The internal-friction of 6066Al/SiC_p is higher than that of 6066A1, especially under high temperature. The internal-friction is mainly caused by dislocation between 300K and 420K, and can be attributed to boundary sliding of interface at temperature higher than 420K.3. DTA results show that the molten temperature and solidification temperature of materials made by PM are about 10℃ lower than that made by casting. The prime temperature (℃ ) and time of solid solution of 6066Al/SiC_p is 520 ℃ /100min, respectively, while 10℃ lower than that of 6066Al, and should be aged at 160℃. Although the primary aging processing is like to 6066Al alloy, the peaking aging time of 6066Al/SiC_p is shortened compared to 6066Al alloy . The reason is that there are much more dislocations and interface in 6066Al/SiC_p than in 6066A1. These dislocations and interface can accelerate the nuclei of precipitated phase and quicken the aging processing.4. Suspended after quenching decrease the tensile strength, yield strength and hardness of 6066Al/SiC_p, but the plasticity can be improved. The more time suspended...