ZF6400/16/30Q型大倾角液压支架的研制

根据义马矿区某矿35030工作面煤层赋存条件,确定了液压支架的工作高度和工作阻力,研制了ZF6400/16/30Q型放顶煤大倾角液压支架。通过对支架的仿真模拟和主要结构件的强度校核,可确保支架设计合理,为大倾角厚煤层的高产高效开采提供安全有力的保障。     

污泥中脂肪族硫低温热解下含硫气体的释放特性

在N2气氛下,对空干基污泥进行了低温热解实验,共检测到5种含硫气体,分别是H2S、SO2、CS2、COS和CH3SH,其中H2S、SO2及CH3SH是主要成分.通过XPS测定污泥样品和焦中各形态硫的变化,发现热解温度低于350,℃时,主要是脂肪族硫分解,其他形态硫变化不大.在此基础上,向污泥中添加了两种脂肪族有机硫,以研究脂肪族硫对含硫气体释放的影响,添加后,发现H2S的释放量剧烈增大,SO2和CH3SH的增加量相对较少,同时H2S释放量的增加促进了COS和CS2的生成.     

氢燃料电池氢气管道吹扫系统冷启动策略研究

针对现有车载燃料电池管道在吹扫过程中氢气侧管道由于低温结冰易受阻,从而导致冷启动困难的问题,提出氢气管道两级吹扫方案,以实现对燃料电池堆氢管中剩余水、蒸汽含量的独立控制,降低冷启动时的加热能耗,避免冷启动失效。通过三维仿真对4种不同工况下阴极中段在不同时间的温度、阴极中段在不同时间的冰体积分数、电池纵向截面表面不同时间的温度进行分析,结果表明该方案可实现在-20 ℃温度下20 s内的平稳冷启动,既解决了低温冷启动困难问题,又保证了冷启动后的电堆输出性能。     

水平热型连铸定向凝固设备研究

设计制造了氩气气氛保护下的水平热型连铸定向凝固设备,该设备将水平连续铸造与定向凝固技术结合起来,集熔炼、保温、净化、凝固于一体,可制备出表面光洁、质量优异的定向凝固线材。介绍了该设备的结构组成、工作原理。     

Correlation between microstructure and tensile behavior of metal–intermetallic laminate compound with different initial Ni foil thickness

Ni-base metal–intermetallic laminate composites were obtained from in situ reaction synthesis between Ni and Al foils by utilizing plasma activated sintering. The effects of Ni foil thickness on the microstructure and tensile properties of the composites were investigated. The results show that the phases forming during reaction synthesis are independent of the starting thickness of the Ni foils. However, thicker reacted layers are obtained in the samples fabricated from 100 lm Ni foils(Ni100) than those obtained in the samples from 50 lm Ni foils(Ni50)when treated at the same process. The tensile strength of Ni100 samples increases with the temperature increasing at the expense of ductility. Dissimilarly, Ni50 composites treated at higher temperatures exhibit enhanced strength and ductility. Both Ni50 and Ni100 laminate fracture in a similar mechanism. Cracking first occurs in the brittle intermetallic layers. These original cracks result in shear bands in Ni layers emitted from the crack tips, and thus producing local stress concentration, which initiates new cracks in adjacent intermetallic layers. The multiplication of cracks and shear bands leads to the failure of the laminates.     

AP1000接管段检测不合格原因分析

材质为SA-508 Gr.3Cl.1的核反应堆压力容器锻件AP1000容器法兰接管段,经锻后正回火处理,在超声检测时发现多处严重超标缺陷。利用扫描电子显微镜、能谱仪、图像分析仪等检测手段进行取样分析,对试样进行低倍断口观察、金相组织检验,利用SEM和EDS对断口的微观形貌和成分进行进一步的分析,结合锻造工艺,确认缺陷性质为白点。其形成原因是由于生产过程中控氢不严使得钢中含有大量氢并发生聚积,在内应力作用下形成裂纹,最终导致检验不合格。通过改善工艺条件,达到消除白点提高产品质量的目的。     

Effects of ZrO2 on the Nitridation Behavior and Mechanical Properties of Reaction-Bonded Si3N4/h-BN Composite

This paper presented a rapid nitridation route to fabricate reaction-bonded Si₃N₄/h-BN ceramic composite by the addition of ZrO₂. The effects of ZrO₂ on the silicon nitridation behavior, microstructure, and mechanical properties of the composite were investigated. The results showed that ZrO₂ could effectively promote the nitridation of silicon and significantly influence the microstructure and mechanical properties of the composite. The best nitridation result, almost full conversion, was achieved when the ZrO₂ content was 8 wt.%, and the outstanding mechanical properties were also exhibited at this condition. TG-DTA and thermodynamic analyses revealed that the inter-conversion between ZrO₂ catalyst and ZrN metastable phase could effectively inhibit microzone melting of silicon and make the fresh surfaces of silicon particles exposed to nitrogen, and consequently accelerated the nitridation of silicon.     

Aermet100钢高温变形行为及热加工图研究

通过热模拟压缩试验研究了Aermet100钢在应变速率为0.01~50 s-1,变形温度为1073~1473 K和变形程度为0.05~0.9条件下的热变形行为,并采用正交分析方法研究了工艺参数(应变、应变速率、变形温度)对Aermet100钢热变形流动应力的影响规律,建立了基于正交分析的回归型Aermet100钢的热变形本构方程。综合考虑应变速率和变形温度对材料微观结构及性能的影响,依据动态材料模型(DMM)建立了基于本构方程的Aermet100钢的热加工图,并利用热加工图确定了Aermet100钢热变形时的流变失稳区,分析讨论了不同区域的Aermet100钢的高温变形特征。     

Interface and Wear Resistance of SiC Ceramic Column Grid Array Reinforced High-Chromium Cast Iron Composite Pretreated with TiH2

利用TiH2粉末膏剂涂覆和在真空下1000或1400℃保温20 min的预处理工艺对反应烧结SiC陶瓷柱进行了表面预处理,再将预处理好的SiC陶瓷柱固定在石墨板上,随后采用金属浇铸工艺制备了一种具有高度陶瓷增强体宏观均匀性、可靠性和可设计性的SiC陶瓷柱阵列增强高铬铸铁复合材料。陶瓷涂层和复合材料界面分析表明:1400℃为较优的SiC表面预处理温度,预处理后SiC表面形成一层可靠的金属性复合层。该复合层在高温浇注过程中不会被溶解,可有效抑制高铬铸铁与SiC陶瓷的界面反应,从而形成无脱层、优良的复合材料陶瓷/金属磨损界面。与该复合材料的金属基体相比,由于SiC陶瓷柱的有效添加,经表面处理后不同陶瓷含量的SiC/高铬铸铁复合材料的耐磨性能均显著提高。     

动筛跳汰排矸车间设计探讨

介绍了动筛跳汰排矸车间设计时通常采取的一些不合理的工艺布置方式及在使用过程中存在的问题,并提出合理化的建议,阐述了动筛跳汰机设备选型需要注意的事项,可为动筛排矸车间的合理设计提供参考。