Study On The Mechanism Of C~+of HIPIB Interaction With Magnesium Alloy AZ31

High intensity pulsed ion beams irradiation into AZ31Magnesium alloy has beencarried out in TIA-450type HIPIB apparatus. HIPIB radiation parameter: pulsevoltage250keV, ion beam current density of170~300A/cm2, energy density2~3J/cm2, pulse width80ns and with shot number of1~100, respectively.SRIM programme simulates the ion range of C~+and H~+, the development ofenergy distribution and crystalline imperfection; Optical Microscope, scanningelectron microscope(SEM), X-ray diffraction(XRD) and Transmission ElectronMicroscope (TEM) methods have been used to investigate the change of crystal grain,surface topography, phase structure and microstructure. The microhardness, wearingand corrosion resistance feature has been measured by microhardness tester,friction-wear test, anodic oxidation and salt spray test. The modification mechanismof HIPIB irradiated AZ31magnesium alloy has been discussed.By SRIM programme simulation: the range of H~+ion is much larger than C~+ionwith the same energy irradiated into the target; energy deposition induced byionization primarily; vacancy defect in the samples has been induced by phonons ofC~+mainly.The results show that the shot numbers of HIPIB irradiation play a great role onthe target morphology, subsequent irradiation on the melting crater has previouslygenerated fuzzy or eliminated the trend; melting craters appear again along with theincreasing the times of irradiation.Metallographic, TEM and XRD analysis show that: the grain structure of themelting layer of the target irradiated by HIPIB has been significantly refined, theβ-Mg17Al12of the irradiated targets solution to the matrix α-Mg grains within theorganization; target bystress waves produce plastic deformation, crystal orientationchanges, there occurs reply slip and recrystallization phenomenon.The average micro-hardness nearly has been3times increased and friction lossesreduced over irradiation; Polarization curves of irradiated samples show a lower corrosion current, corrosion potential and critical breakdown potential were increasedby140mV and720mV respectively; surface morphology of the salt spray corrosiondemonstrates that the original target has serious corrosion crackings and largecorrosion products, the irradiated target surface corrosion is reduced significantly.