热处理对粉末冶金法制备Wp/2024Al复合材料力学性能的影响

利用粉末冶金法制备了钨颗粒体积分数分别为5%,8%,10%的Wp/2024Al复合材料,挤压态复合材料W颗粒分散均匀,沿挤压方向钨颗粒呈带状分布。复合材料经过热处理后拉伸强度得到提高,延伸率则发生下降;同一工艺制备的Wp/2024Al复合材料480℃固溶时抗拉强度达到最大值;随着固溶温度的升高,复合材料屈服强度有一定的增加,延伸率下降;随着W含量的增加,T4态复合材料的抗拉强度和屈服强度升高,而延伸率下降。断口观察表明,挤压态和热处理态复合材料断口上存在大量韧窝,W颗粒没有发生开裂,热处理态复合材料发生界面脱开现象。     

SPS烧结W-TaC的耐瞬态热冲击性能

通过高能球磨方法制备了系列W-TaC混合粉末,采用放电等离子体烧结(SPS)制备出弥散强化W-TaC样品,并对W-TaC样品的密度、硬度和微观组织进行了分析。利用60 k W电子束材料测试平台(EMS-60)对烧结W-TaC的耐瞬态热冲击性能进行测试,分别模拟了等离子体破裂和边缘局域模2种热负荷。实验后通过扫描电镜观察了样品加载区域的裂纹及熔化情况,通过透射电镜观察分析了材料的微结构特征。结果表明:W-TaC样品在热负荷作用下可以经受功率密度为740 MW/m~2、5 ms的热冲击而不产生裂纹,但在功率密度为550 MW/m~2、100次1 ms的热疲劳下会产生疲劳微裂纹。SEM和TEM分析表明,TaC颗粒在钨晶粒内和晶粒间都有存在,而且TaC会与W形成共格相界和半共格晶界从而增强钨合金的强度。     

钨/低活化钢连接用Fe基非晶钎料

采用单辊急冷技术制备Fe_(60)Mn_(15)B_(16.67)Si_(6.33)Sn_2非晶箔带,将其作为钎料对DEMO聚变示范堆偏滤器用钨与低活化钢进行了钎焊连接。结果表明:1220℃温度下保温15 min所获得的钎焊接头界面结合良好,无孔洞、裂纹等宏观缺陷,其焊缝组织由单相Fe基固溶体、混合相层(固溶体基体上分布着(Fe,Cr)_3B与FeW_2B_2相)和FeW_2B_2基化合物层3部分构成;基于合金组元的扩散与交互作用,揭示了钎焊接头组织特征与相关形成机制。     

变形量对纯钨热导率及再结晶温度的影响

采用粉末冶金及高温锻造工艺制备了3种规格的纯钨棒材,研究了不同变形量钨棒的微观组织、热导率及再结晶温度的差异。结果表明,随着变形量的增加,纯钨棒的相对密度和维氏硬度都呈现出先快速上升后趋于平缓的趋势,晶粒长径比逐渐增大且晶粒组织逐渐细化,最终呈现出纤维状。由于密度提升及孔隙率降低,纯钨棒的热导率及热扩散系数都随对数应变的增大有一定的提升,而当纯钨棒趋于完全致密化后,其热导率差异较小。对数应变为1.57的纯钨棒的再结晶温度最高,约为1 520℃。经1 450℃保温1 h退火后,对数应变0.88的纯钨棒整体晶粒组织已经明显变大,而对数应变为2.95的纯钨棒已经形成等轴晶。对数应变为2.95的纯钨棒再结晶后的晶粒组织比对数应变为0.88和1.57的要更加均匀细小。     

Behavior of Brazed W/Cu Mockup Under High Heat Flux Loads

In order to transfer the heat from the armor to the coolant, tungsten has to be connected with a copper heat sink. The joint technology is the most critical issue for manufacturing plasma facing components. Consequently, the reliability of the joints should be verified by a great number of high-heat-flux （HHF） tests to simulate the real load conditions. W/Cu brazed joint technology with sliver free filler metal CuMnNi has been developed at Southwestern Institute of Physics （SWIP）. Screening and thermal fatigue tests of one small-scale fiat tile W/CuCrZr mockup were performed on a 60 kW electron-beam Material testing scenario （EMS-60） constructed recently at SWIP. The module successfully survived screening test with the absorbed power density （Pabs） of 2 MW/m2 to 10 MW/m2 and the following 1000 cycles at Pabs of 7.2 MW/m2 without hot spots and overheating zones during the whole test campaign. Metallurgy and SEM observations did not find any cracks at both sides and the interface, indicating a good bonding of W and CuCrZr alloy. In addition, finite element simulations by ANSYS 12.0 under experimental load conditions were performed and compared with experimental results.     

增材方向对激光粉末床熔融钨材料抗高热负荷性能的影响

激光粉末床熔融(LPBF)作为一种新兴的增材制造技术,为未来聚变堆偏滤器mono-block的制备提供了新的成形方法.本研究利用LPBF,采用水平增材和竖直增材2种方式对纯钨样品进行了制备.研究发现,在15 MW/m2的热负荷下,竖直增材样品发生了明显的熔化和飞溅现象,水平增材样品只发生少许开裂和轻微溅射.通过微观组织...     

W/CuCrZr合金热等静压焊接

采用热等静压(HIP)焊接技术制备W/Cu Cr Zr偏滤器部件焊接模块,分别研究以物理气相沉积(PVD)制备的40μm铜涂层作为过渡层,以2 mm厚的TU1铜片作为过渡层以及无过渡层3种结构模块的焊接界面质量。通过扫描电子显微镜(SEM)、超声波无损探伤仪(NDT)、力学拉伸试验机和电子束高热负荷试验装置分别对焊接模块的微观形貌、焊接缺陷、力学性能和高热负荷性能进行检测分析。结果表明:HIP焊接工艺参数为(940℃,120MPa,2 h)时,采用40μm铜涂层为过渡层的模块焊接界面结合质量最高,且没有缺陷,经过入射功率密度为20MW/m2的高热负荷试验也没有失效。因此,该工艺是3种工艺参数下钨/铜合金偏滤器模块制造的最佳制备技术。     

Numerical Study of High Heat Flux Performances of Flat-Tile Divertor Mock-ups with Hypervapotron Cooling Concept

The hypervapotron (HV), as an enhanced heat transfer technique, will be used for ITER divertor components in the dome region as well as the enhanced heat flux first wall panels. W-Cu brazing technology has been developed at SWIP (Southwestern Institute of Physics), and one W/CuCrZr/316LN component of 450 mm×52 mm×166 mm with HV cooling channels will be fabricated for high heat flux (HHF) tests. Before that a relevant analysis was carried out to optimize the structure of divertor component elements. ANSYS-CFX was used in CFD analysis and ABAQUS was adopted for thermal–mechanical calculations. Commercial code FE-SAFE was adopted to compute the fatigue life of the component. The tile size, thickness of tungsten tiles and the slit width among tungsten tiles were optimized and its HHF performances under International Thermonuclear Experimental Reactor (ITER) loading conditions were simulated. One brand new tokamak HL-2M with advanced divertor con?guration is under construction in SWIP, where ITER-like ?at-tile divertor components are adopted. This optimized design is expected to supply valuable data for HL-2M tokamak.