Hardness, friction and wear characteristics of electrodeposited RE Ni W P B 4C PTFE composite coatings were studied, and the reason for these fine characteristics was explained in respect of structure. The results sho...Hardness, friction and wear characteristics of electrodeposited RE Ni W P B 4C PTFE composite coatings were studied, and the reason for these fine characteristics was explained in respect of structure. The results show that 1) the structure of RE Ni W P B 4C PTFE composite coatings experiences a transformation process from amorphous to mixture then to crystal as the heat treatment temperature rises; 2) incorporating of B 4C greatly increases the hardness of the coating; 3) the wear resistance of the coating is best with heat treatment for 1?h at 300?℃, which is greatly superior to that of the other traditional coatings.展开更多
The -pH diagram of Ni-W-P-H2O system at 298.15 K,10 1325 Pa was plotted by thermodynamic calculation software FactSageTM 5.1. The results show that tungsten and phosphorus can be co-deposited with nickel in type of ...The -pH diagram of Ni-W-P-H2O system at 298.15 K,10 1325 Pa was plotted by thermodynamic calculation software FactSageTM 5.1. The results show that tungsten and phosphorus can be co-deposited with nickel in type of Ni4W,Ni3P,Ni5P2,respectively. XRD analysis shows that the main phase of RE-Ni-W-P-B4C coatings is amorphous as deposited. After heated at 673 K for 3 h,part phases change to crystalline which are Ni,Ni3P,P,W,Ni3C,Ni3B,CeO2. SEM shows the micrograph of the coatings is even and the solid particles scatter well. The thickness of the coating is 2 219 μm after electroplating for 96 h. The micro-hardness of the coatings is HV 825-HV 1 097 as-deposited and increases to HV 1 236 after heat treated. The wear resistance of the coatings is good and the friction coefficient changes from 0.10 to 0.33 during the abrasion process. The resistance to oxidation of the composite coatings is better than Ni-W-P alloy coatings and worse than that of RE-Ni-W-P-SiC coatings.展开更多
使用MCNP5程序模拟了能量为14.88 Me V的快中子在(W+B_4C)/Al和W/Al复合材料中的输运过程,并与铅硼聚乙烯、聚乙烯以及钨进行对比。计算了各屏蔽材料的中子衰减性能、中子透射能谱以及中子俘获过程中释放γ射线的透射能谱,为中子屏蔽材...使用MCNP5程序模拟了能量为14.88 Me V的快中子在(W+B_4C)/Al和W/Al复合材料中的输运过程,并与铅硼聚乙烯、聚乙烯以及钨进行对比。计算了各屏蔽材料的中子衰减性能、中子透射能谱以及中子俘获过程中释放γ射线的透射能谱,为中子屏蔽材料的选择提供了理论依据。模拟结果和实际结果吻合,证实了蒙特卡罗方法的可靠性。模拟结果也可以得出,对于快中子,高原子序数材料的屏蔽效果要好于低原子序数材料,含钨45%的复合材料的屏蔽性能与商用铅硼聚乙烯的屏蔽效能相近,但是激发γ射线能量低于铅硼聚乙烯,考虑到成分可调控性、使用温度以及力学性能等因素,(W+B_4C)/Al复合材料是一种极具应用潜力的新型中子屏蔽材料。展开更多
文摘Hardness, friction and wear characteristics of electrodeposited RE Ni W P B 4C PTFE composite coatings were studied, and the reason for these fine characteristics was explained in respect of structure. The results show that 1) the structure of RE Ni W P B 4C PTFE composite coatings experiences a transformation process from amorphous to mixture then to crystal as the heat treatment temperature rises; 2) incorporating of B 4C greatly increases the hardness of the coating; 3) the wear resistance of the coating is best with heat treatment for 1?h at 300?℃, which is greatly superior to that of the other traditional coatings.
基金Project (2005XZ1) supported by the Scientific Research Key Foundation of Wuhan University of Science and Technology, China
文摘The -pH diagram of Ni-W-P-H2O system at 298.15 K,10 1325 Pa was plotted by thermodynamic calculation software FactSageTM 5.1. The results show that tungsten and phosphorus can be co-deposited with nickel in type of Ni4W,Ni3P,Ni5P2,respectively. XRD analysis shows that the main phase of RE-Ni-W-P-B4C coatings is amorphous as deposited. After heated at 673 K for 3 h,part phases change to crystalline which are Ni,Ni3P,P,W,Ni3C,Ni3B,CeO2. SEM shows the micrograph of the coatings is even and the solid particles scatter well. The thickness of the coating is 2 219 μm after electroplating for 96 h. The micro-hardness of the coatings is HV 825-HV 1 097 as-deposited and increases to HV 1 236 after heat treated. The wear resistance of the coatings is good and the friction coefficient changes from 0.10 to 0.33 during the abrasion process. The resistance to oxidation of the composite coatings is better than Ni-W-P alloy coatings and worse than that of RE-Ni-W-P-SiC coatings.
文摘使用MCNP5程序模拟了能量为14.88 Me V的快中子在(W+B_4C)/Al和W/Al复合材料中的输运过程,并与铅硼聚乙烯、聚乙烯以及钨进行对比。计算了各屏蔽材料的中子衰减性能、中子透射能谱以及中子俘获过程中释放γ射线的透射能谱,为中子屏蔽材料的选择提供了理论依据。模拟结果和实际结果吻合,证实了蒙特卡罗方法的可靠性。模拟结果也可以得出,对于快中子,高原子序数材料的屏蔽效果要好于低原子序数材料,含钨45%的复合材料的屏蔽性能与商用铅硼聚乙烯的屏蔽效能相近,但是激发γ射线能量低于铅硼聚乙烯,考虑到成分可调控性、使用温度以及力学性能等因素,(W+B_4C)/Al复合材料是一种极具应用潜力的新型中子屏蔽材料。
