摘要
Specimens of silicon carbide(6H-SiC)were irradiated with 5 MeV Kr ions(84Kr19+)for three fluences of 5×10^(13),2×10^(14) and 1×10^(15) ions/cm^(2),and subsequently annealed at room temperature,500°C,700°C and 1000°C,respectively.The strain of the specimens was investigated with high resolution XRD and different defect evolution processes are revealed.An interpretation of the defect evolution and migration is given to explain the strain variation.The mechanical properties of the specimens were studied by using a nano−indentation technique in continuous stiffness measurement(CSM)mode with a diamond Berkovich indenter.For specimens irradiated with fluences of 5×10^(13) or 2×10^(14) ions/cm^(2),hardness values exceed that of un−implanted SiC.However,hardness sharply degrades for specimens irradiated with the highest fluence of 1×10^(15) ions/cm^(2).The specimens with fluences of 5×10^(13) and 2×10^(14) ions/cm^(2) and subsequently annealed at 700°C and 500°C,respectively,show the maximum hardness value.
基金
Supported by the National Natural Science Foundation of China under Grant Nos.10575124 and 10979063
the National Basic Research Program of China under Grant No.2010CB832904.
