Study On Preparation And Mechanical Properties Of B/WAl And (W_f+B)/Al Composites

As a safe and efficient clean energy,nuclear energy has been widely used in radiation medicine,nuclear industry,nuclear weapons and other fields,and has become the most promising energy in the future.However,in the wide application of nuclear energy,it will inevitably bring about the harm of nuclear radiation.Therefore,it is very important to develop efficient and stable nuclear shielding materials.In this paper,B/WAl and(W_f+B)/6061Al composites were prepared.Firstly,the preparation process of tungsten-aluminum alloy powder was optimized by mechanical alloying,and the optimal process parameters were determined.On this basis,B/WAl composite was prepared by using tungsten-aluminum alloy as matrix and amorphous boron particles as reinforcement system,and the microstructure and mechanical properties of the composite were characterized.The microstructure and mechanical properties of(W_f+B)/6061Al composites were characterized by using cut tungsten fibers and amorphous boron particles as reinforcement.In the preparation of tungsten-aluminum alloy powder,the effects of surfactant type,surfactant content and tungsten particle size on the mechanical alloying process of tungsten-aluminum alloy powder were investigated with W_43.75Al_56.25 as the research object.It was found that the mechanical alloying of tungsten-aluminum alloy powder could be completely achieved by adding 1ml OP-10 surfactant and milling with 3?m tungsten powder for 65h.The grain size and lattice constant of the powders obtained are smaller,which are the optimal process parameters.B/WAl composites were prepared by SPS sintering process.The mechanical properties and microstructure of the composites sintered at 1000?and 1100?were studied,and the microstructure of the composites sintered at 1300?was observed.The results show that the densities of the composites sintered at 1000?,1100?and 1300?are 8.01,9.09 and 13.68g/cm³,respectively.When the sintering temperature is increased from 1000?to 1100?,the bending strength,compression strength and elastic modulus of the composites are all increased.Large pores and small pores exist in the composites sintered at 1000,1100 and 1300?,and a large amount of Al element precipitates and segregates in the composites sintered at 1300?.The(W_f+B)/6061Al composites were prepared by SPS sintering process.It was found that the composites were compact enough at different sintering temperatures and holding time.With the increase of sintering temperature and holding time,the tensile strength and bending strength of the composites decreased.The tungsten fibers are uniformly distributed in the matrix and closely bonded to the matrix without obvious pores and interfacial reaction layers.The effects of tungsten fiber diameter,volume fraction and solution aging on the mechanical properties of(W_f+B)/6061Al composites were investigated.It was found that with the increase of tungsten fiber diameter,the strength and elongation of the composites decreased,but the strength changed little.With the increase of the volume fraction,the strength of the composites increases,the elongation decreases,and the elastic modulus first increases and then tends to be stable.After T6 treatment,the elongation of the composites decreases,the tensile strength of the 10vol.%and 20vol.%tungsten fiber reinforced composites increases significantly,and the tensile strength of the 30vol.%composites decreases.There are energy dissipation mechanisms such as interfacial debonding and ductile deformation.