The effect of plasma arc powder surfacing process on the amount of B4C particles in the coating and the thermal behavior of B4C particles in different surfacing stages has been investigated.The results showed that the...The effect of plasma arc powder surfacing process on the amount of B4C particles in the coating and the thermal behavior of B4C particles in different surfacing stages has been investigated.The results showed that the feeding rate of B4C partiles is the most important factor affecting the amount of B4C particles in the surfacing coating among all the surfacing parameters,and the most part of B4C Particles in the coating is nto the remainders of original solid B4C particles,but the consolidation products of the unmelted liquid B4C globules in the pool.The results also showed that the B4C particles would not be melted in the plasma arc column, their melting process mainly takes place in the anode spot region on the surface of the pool when surfacing current is less than 200A.展开更多
The B4C/Mg composites fabricated by metal-assisted pressureless infiltration technique were used as experimental material, and the wear behavior and mechanism of this material were studied. A pin-on-disc apparatus was...The B4C/Mg composites fabricated by metal-assisted pressureless infiltration technique were used as experimental material, and the wear behavior and mechanism of this material were studied. A pin-on-disc apparatus was used to evaluate the wear behavior where loads of 20, 40, 60 and 80 N, and a sliding velocity of 250 r/min were exerted. The results show that B4C/Mg composites possess superior wear resistance than pure Mg under various applied loads, and the content of Ti, as infiltration inducer, has an influence on the wear resistance of B4C/Mg composites. The dominant wear mechanism for pure Mg is abrasion, while that for B4C/Mg composites under low loads is adhesion and delamination. Under high loads, the wear mechanism of B4C/Mg composites can be attributed to thermal softening and melting or plastic deformation.展开更多
Boron carbide/natural rubber latex(B_4 C/NRL)flexible films were prepared via dip-molding with B_4 C content in the range of 5–55 wt% for thermal neutron(0.0253 e V) shielding. B_4 C was well dispersed in NRL accordi...Boron carbide/natural rubber latex(B_4 C/NRL)flexible films were prepared via dip-molding with B_4 C content in the range of 5–55 wt% for thermal neutron(0.0253 e V) shielding. B_4 C was well dispersed in NRL according to microscopic observation. Both the inside and outside surfaces of the film were smooth. For B_4 C/NRL flexible films, the minimum elongation at break was greater than 600%, the minimum tensile strength was greater than 12 MPa, and the hardness was in the range of 35–55 HA,which were suitable for preparing flexible wearable products. The attenuation efficiencies of the B_4 C/NRL flexible films for thermal neutrons were also calculated. The B_4 C/NRL flexible films exhibit good attenuation effect for thermal neutrons.展开更多
文摘The effect of plasma arc powder surfacing process on the amount of B4C particles in the coating and the thermal behavior of B4C particles in different surfacing stages has been investigated.The results showed that the feeding rate of B4C partiles is the most important factor affecting the amount of B4C particles in the surfacing coating among all the surfacing parameters,and the most part of B4C Particles in the coating is nto the remainders of original solid B4C particles,but the consolidation products of the unmelted liquid B4C globules in the pool.The results also showed that the B4C particles would not be melted in the plasma arc column, their melting process mainly takes place in the anode spot region on the surface of the pool when surfacing current is less than 200A.
基金Project(51271051)supported by the National Natural Sciecne Foundation of China
文摘The B4C/Mg composites fabricated by metal-assisted pressureless infiltration technique were used as experimental material, and the wear behavior and mechanism of this material were studied. A pin-on-disc apparatus was used to evaluate the wear behavior where loads of 20, 40, 60 and 80 N, and a sliding velocity of 250 r/min were exerted. The results show that B4C/Mg composites possess superior wear resistance than pure Mg under various applied loads, and the content of Ti, as infiltration inducer, has an influence on the wear resistance of B4C/Mg composites. The dominant wear mechanism for pure Mg is abrasion, while that for B4C/Mg composites under low loads is adhesion and delamination. Under high loads, the wear mechanism of B4C/Mg composites can be attributed to thermal softening and melting or plastic deformation.
基金supported by the National Natural Science Foundation of China(No.11405149)the Sichuan Academic and Technical Leader Program(No.DTR201501)
文摘Boron carbide/natural rubber latex(B_4 C/NRL)flexible films were prepared via dip-molding with B_4 C content in the range of 5–55 wt% for thermal neutron(0.0253 e V) shielding. B_4 C was well dispersed in NRL according to microscopic observation. Both the inside and outside surfaces of the film were smooth. For B_4 C/NRL flexible films, the minimum elongation at break was greater than 600%, the minimum tensile strength was greater than 12 MPa, and the hardness was in the range of 35–55 HA,which were suitable for preparing flexible wearable products. The attenuation efficiencies of the B_4 C/NRL flexible films for thermal neutrons were also calculated. The B_4 C/NRL flexible films exhibit good attenuation effect for thermal neutrons.
