频谱谐波时效消除焊接结构件应力的工艺研究

对频谱谐波时效工艺代替热时效工艺降低、均化工件残余应力,保证焊接结构件生产过程中尺寸的精度和应用中可靠性进行论证、试验,阐述了频谱谐波时效的定义及作用,给出判定振动消除应力效果有效原则。     

振动时效在推土机后桥箱焊接过程中的应用

为了消除推土机后桥箱焊接后的残余应力,应用JB／T5926-1991《振动时效工艺参数选择及技术要求》标准对振动时效工艺进行了定性的评价。通过对工件振动时效前后的对比,了解振动时效工艺对焊接残余应力的变化。并通过了解振动时效工艺的可行性和有效性,降低了制作成本,提高了生产效率。     

振动时效在风电塔筒制造中的应用

为了消除风电塔筒基础环拼接下法兰的焊接残余应力,应用JB/T5926—1991《振动时效工艺参数选择及技术要求》标准对振动时效工艺进行了定性的评价。通过对工件振动时效前后曲线的对比,了解振动时效工艺对焊接残余应力的变化。并通过了解振动时效工艺的可行性和有效性,降低了制作成本,提高生产效率。     

LD2锻铝稳定化处理的研究

本文采用光镜、电子显微镜、X射线衍射仪、X射线应力分析仪及测定机械性能的方法对工业锻铝合金LD₂的固溶处理、时效和稳定化处理对组织、性能、应力及尺寸稳定性的影响进行了试验研究。研究认为在获得较好综合机械性能的情况下,控制固溶化条件、淬火介质温度、时效温度及时间和冷热循环稳定化处理条件,可以稳定组织,减少残余应力,满足尺寸稳定性的要求。从而提出了适合于精密机械与仪器中高尺寸稳定性的零件的最佳工艺规程     

振动时效在水电设备上的对比应用

通过对振动时效和热时效消除工件残余应力的对比试验,证明两种时效工艺的效果基本相近,振动时效可部份取代传统的热时效,可推广应用,达到降低时效成本,提高生产效率,节能减排的目的。     

热处理工艺参数对无磁铸铁组织与性能的影响

探讨了时效温度及时效时间对无磁铸铁组织和性能的影响,获得了对生产具有指导意义的工艺能数。     

水轮发电机机座振动时效试验研究

通过对水轮发电机机座振动时效与热时效前后的残余应力检测试验的对比研究，结果两者的应力消除率相近，均为54％左右；说明对于机座等焊接构件的时效处理，用振动时效工艺取代传统的热时效工艺是可行的，对于企业降低成本及提高生产效率具有重要意义，能产生显著的经济效益。     

16V240ZJ柴油机钢曲轴加工工艺的改进

曲轴是柴油机的关键零部件,形状复杂,刚度差,技术要求高,加工工艺复杂、加工余量大、生产成本高。从锻坯投入到出成品要经过数十道加工工序,其中包括调质、时效、中频淬火及低温回火等工序。为了提高生产效率,缩短曲轴生产周期,本文运用残余应力的实验研究结果,对曲轴加工中产生的残余应力进行分析,发现时效在整个曲轴工艺中所起的作用极小,与磨削裂纹的发生和成品曲轴尺寸稳定性无关。提出了取消时效和半精加工,减少粗加工留量的改进工艺。经表面残余应力测试和工艺试验,证明     

用振动调整焊接构件残余应力的应用与研究

本文介绍了振动时效工艺的特点,机理及振动时效参数与时效工艺效果的关系,在大量试验的基础上,详细论述了振动时效工艺的检测方法及技术效果分析,研究的结果对振动时效工艺的推广应用,合理的制订检验,验收标准、工艺参数,提供了有价值经验和科学依据。     

铍青铜QBe2合金形变热处理工艺的优选

对铍青铜QBe2合金的形变热处理工艺进行了优选。试验表明,控制冷变形度与时效温度可获得高的弹性极限和硬度。文中给出了QBe 2合金形变热处理最佳工艺参数,以便在生产中采用。     

Na2O-B2O3-Ta2O5系统玻璃红外光谱的研究

本文首次系统地研究了Na₂O—B₂O₃—Ta₂O₅。三元新系统的红外光谱,分析了B₂O₃、Ta₂O₅含量的变化对玻璃结构的影响。结果表明:随着Na₂O/B₂O₃比值的减小,结构中:[BO₄]四面体减小,[BO₃]三角体增加。随着Ta₂O₅含量的增加,[BO₄]四面体的数量增多,非桥氧的数量减少,表明Ta⁵⁺可以连结非桥氧,形成网络。     

Electron and light microscopy studies on the domain structures of Zn3B7O13Cl, Zn3B7O13Br and Zn3B7O13I ferroic boracites

The domain structures of Zn₃B₇O₁₃Cl, Zn₃B₇O₁₃Br and Zn₃B₇O₁₃I boracite single crystals were studied by means of polarized light in conjunction with electron microscopy. Single crystals of the three compositions were grown by chemical transport reactions in closed quartz ampoules, at a temperature of 900 °C and were examined by polarizing optical microscopy (PLM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). For both PLM and SEM, the same as‐grown samples were used without having to resort to metallization of the crystal faces. For TEM the single crystals were crushed and mounted on holey carbon films. Comparative electron microscope images were useful for revealing the domain structure of these ferroelectric/ferroelastic materials previously observed between the crossed polars of an optical microscope. X‐ray diffraction analysis of the pulverized crystals was performed for this triad of halogen boracites containing zinc as a common metal.     

B2O3—La2O3—BaO—Nb2O5系统的玻璃生成范围及其性质

本文研究了在B₂O₃-La₂O₃-BaO-Nb₂O₅四元系统中当B₂O₃含量分别为25、30、35wt%时,该系统的玻璃生成范围和它们的光性、密度等变化规律。结果表明,随着B₂O₃含量的增加,系统的玻璃生成范围向贫Nb₂O₅边界扩充,富Nb₂O₅边表现收缩。工作中得出了该系统分别以SiO₂代B₂O₃、Al₂O₃代BaO后的析晶、折射率、色散及密度等性质的变化规律。最后应用该系统研制定型了713/538玻璃。     

Ta2O5对B2O3-La2O3-CaO系统玻璃生成范围的影响

本文研究了在B₂O₃—La₂O—CaO三元系统中,当Ta₂0₅的含量分别为5、10、15、20wt%时,该系统的玻璃生成范围.结果表明,随着Ta₂O₅含量的增加,系统的玻璃生成范围向贫B₂O₃,富La₂O₃边界扩充.当Ta₂O₅的含量为10wt%时,玻璃的生成区域最大.通过差热分析确定了玻璃析晶温度,并用X射线衍射进行了物相鉴定.结果表明,随Ta₂O₅取代La₂₃其主结晶相的放热峰或吸热峰的位置变化不同,所析出的结晶物质亦不同.     

Tribological performance of MoS2---B2O3 compacts

A recent investigation suggests that selected oxides perform well as additives in molybdenum disulphide (MoS₂) because of their ability to soften at asperity contacts with the result that the solid lubricant can attain and retain a preferred tribological orientation.This research determined the effectiveness of boric oxide (B₂O₃), when used as an additive in MoS₂, for substrate temperatures ranging from 21°C to 316°C. This range was used to allow the asperity contact temperature to vary below and above the softening point of B₂O₃. It was found that a moderate friction coefficient and high wear, which is attributed to the additive acting abrasively, occurred when the asperity contact temperature was well below the softening point of the oxide. When the asperity contact temperature neared the softening point of the oxide, the friction coefficient increased dramatically and wear volume was reduced. It is postulated that B₂O₃ acted adhesively at the interface resulting in a higher coefficient of friction, and wear decreased due to an attainment of a preferred orientation by the MoS₂. For asperity contact temperatures significantly above the softening point of B₂O₃, the friction coefficient returned to about the same value as for temperatures below the softening point. It is speculated that wear continued to increase moderately because of localized melting of the B₂O₃, permitting the MoS₂ to be removed from the interface. These observations support a hypothesis that an additive, such as boric oxide, can soften as the asperity contact temperature approaches the softening point temperature of the additive so that the overall tribological conditions may be improved resulting in reduced interfacial wear. Significant changes in temperature, load or sliding velocity would, of course, dramatically alter the wear characteristics observed at the interface.     

Nb2O5-B2O3-K2O系统玻璃的结构与性质

本工作用大功率转靶 X 射线衍射仪研究铌硼酸盐玻璃结构;根据 B·E·War-ren 方程,建立了一种计算玻璃原子径向分布函数(RDF)的解析方法。因其涉及因素少,计算简便,适用于多元系统玻璃结构分析。应用本方法,已获得了 Nb-B-K 系统玻璃的比较完整的三维结构模型。模型表明,这种玻璃结构松散,克分子体积比较大,并具有较高的自激发极化率。于是铌硼酸盐玻璃的低密度、低折射率和相对高的色散,以及较高的电导率等特殊性质的结构因素得到了证实。     

基于Ge2Sb2Se4Te1的可重构光开关的仿真

光开关是集成光路上一个重要的元器件。提出了一种用在L和C波段基于硫系相变材料（Ge₂Sb₂Se₄Te₁）的片上2×2定向耦合器式的可重构光开关,可通过改变相态切换开关。利用仿真软件Lumerical中的Mode Solutions和FDTD Solutions模块设计器件,得到在1500~1625 nm内耦合长度为24.9 μm的Ge₂Sb₂Se₄Te₁非晶态下插入损耗（IL）>-0.36 dB,串口对比度（CT）<-24 dB;Ge₂Sb₂Se₄Te₁晶态下IL>-0.44 dB,CT<-30.46 dB。利用仿真软件COMSOL模拟532 nm波长激光加热Ge₂Sb₂Se₄Te₁,结果显示：一个25 ns、峰值功率45 mW的高斯短脉冲可以使材料由晶态转化为非晶态;施加多个峰值功率20 mW、周期1 μs且占空比0.03%的高斯脉冲阵列可重回晶态。仿真结果表明,设计的光开关在通信波段通过激光加热可以快速实现切换光路的作用。     

Characterization of cast Al86Mn3Be11 alloy

An Al₈₆Mn₃Be₁₁ alloy cast into copper mould was subjected to metallographic investigation. The as-cast microstructure consisted of a quasicrystalline icosahedral phase (i-phase), Be₄AlMn phase and, occasionally, a hexagonal phase. Al-rich solid solution represented the dominant phase. The chemical compositions of phases were determined using AES. The composition of the Be₄AlMn slightly deviated from the stoichiometric composition, whereas the composition of the i-phase was approximately Al₅₂Mn₁₈Be₃₀, containing an appreciable amount of Be. The average composition of the hexagonal phase was Al₆₆Mn₂₁Be₁₃. Deep etching and particle extraction provided a deep insight into the three-dimensional morphology of the i-phase and the hexagonal phase, whereas Be₄AlMn was slightly attacked by the etchant. The i-phase was present predominantly in the form of dendrites and a rodlike eutectic phase. The hexagonal phase was primarily in the form of hexagonal platelets, whereas Be₄AlMn was rather irregular in shape. The morphology of the i-phase can be explained by predominant growth in 3-fold directions and the lowest energy of the 5-fold planes, leading to the faceting and adopting a pentagonal dodecahedron shape. The brightnesses of phases in the backscattered electron images were rationalized by determining their backscattering coefficients. TEM investigation showed considerable phason strain in the i-phase, and the polycrystalline nature of the Be₄AlMn phase.     

Al2O3-TiB2-ZrO2三元复合陶瓷刀具的性能研究

对Al     

Tribological properties of ZrO2 (Y2O3)-Mo-BaF2/CaF2 composites at high temperatures

ZrO₂ (Y₂O₃) with different contents of BaF₂/CaF₂ and Mo were fabricated by hot pressed sintering, and the tribological behavior of the composites against SiC ceramic was investigated from room temperature to 1000 °C. It was found that the ZrO₂ (Y₂O₃)-5BaF₂/CaF₂-10Mo composite possessed excellent self-lubricating and anti-wear properties. The low friction and wear were attributed to enhanced matrix and BaMoO₄ formed on the worn surfaces.