一种由MCNP设计,通过SPS加热轧制备的新型辐射屏蔽复合材料

A newly designed radiation shielding composite by MCNP and fabricated by SPS followed by hot-rolling

摘要:

本研究旨在设计和制备一种新型的中子和γ射线辐射屏蔽复合材料。基于蒙特卡罗模拟,含不同W质量分数(40~70%)的新型(W+B)/6061Al复合材料首次采用球磨法和SPS加热轧制法制备,并对其组织和力学性能进行了研究。实验结果显示,轧制之后,W和B颗粒均匀分布于基体中,而且W/Al界面以固溶体的形式呈现出良好的冶金结合。复合材料的物相主要包括W和Al。EBSD结果表明,W颗粒具有促进动态再结晶(DRX)成核、限制晶粒长大和降低6061Al基体织构的作用。拉伸试验表明,W含量为50 wt.%的复合材料强度最高,塑性较好。结合模拟结果,该组分的复合材料性能达到了实际应用要求。(W+B)/6061Al复合材料的强化机理包括位错强化和载荷传递效应。

Abstract:

This study aims to design and fabricate a new kind of radiation shielding composite against both neutron and gamma rays. Based on Monte Carlo simulations, novel (W+B)/6061Al composite sheets with different W mass fractions (40-70%) were first fabricated by ball-milling and SPS followed by hot-rolling, then the microstructure and mechanical properties were investigated. Results show that after rolling process, W and B particles uniformly distributed in the matrix and the interface of W-Al exhibited good metallurgical bonding containing solid solution. The composites were mainly consisted of W and Al phases. EBSD results show that W particles had the effects of promoting dynamic recrystallization (DRX) nucleation, confining the grain growth and reducing the texture of 6061Al matrix. Through tensile tests, the composite with 50 wt.% W shows the highest strength and better plasticity. Together with the simulation results, composite of this composition is believed to meet the demand of practical applications. The strengthening mechanisms of (W+B)/6061Al composites include dislocation strengthening and load transfer effect.