Effect of the structure of a VST2K titanium alloy on its machinability

The influence of the chemical composition and different types of heat treatment on the structure formation and the hardness of a VST2K titanium alloy is studied. The dependence of the heat and pressure cutting parameters on the chemical composition, the structure, and the hardness of the VST2K alloy is found. The minimum cutting force and the temperature of samples with a hardness of 35–36 HRC in the cutting zone are determined. It is found that the dependence of the temperature–force parameters of the structural state of the alloy increases with molybdenum equivalent [Mo]_eq. The correlation between the geometric parameters of chips with the machinability is studied. It is shown that the distance between the shear bands having formed in a chip structure can be used to estimate the machinability of the alloy only within one composition and that additional hydrogen alloying of the VST2K alloy degrades the machinability.     

镁合金板带铸轧技术与进展

镁合金板材的应用需求正在扩大,而板带连续铸轧一直被认为是制造镁合金薄板的一种最有效的生产方式。通过综合回顾镁合金板材轧制技术和板材铸轧技术的发展与现状,分析讨论各种连续铸轧和半固态铸轧的工艺技术特点及其优缺点,并介绍了镁合金板带铸轧的新技术发展动向以及金属强制均匀化理论技术在铸轧镁合金薄板中的优越性和适用性。实验结果表明,金属熔体强制均匀化处理和加工成形可有效增加均质熔体的形核率,对合金凝固组织的均匀化、细化效果显著。     

Structure,properties, and production of Zial powder alloy for gas absorbers

Calcium-hydride production technology for Zial (Zr-16Al) alloy is developed. In contrast to powder obtained by the grinding of cast alloy, powder produced by calcium-hydride technology is more disperse, with a highly developed particle surface. A method is developed for determining the sorptional capacity of Zial alloy in hydrogen. It is found that Zial powder produced by calcium-hydride technology matches powder obtained from cast alloy in terms of hydrogen sorption and is preferable in terms of carbon-monoxide sorption. X-ray phase analysis shows that gas absorbers made from Zr-16 Al powder produced by the calcium-hydride technology consist mainly of intermetallics Zr₃Al₂, Zr₅Al₃, and Zr₄Al₃. This composition is optimal when using Zial alloy as a getter     

快淬纳米晶/非晶Mg2-xLaxNi (x=0～0.6)合金的贮氢动力学

为了改善Mg2Ni型合金气态及电化学贮氢动力学性能,用La部分替代合金中的Mg,用快淬技术制备了Mg2-xLaxNi(x=0,0.2,0.4,0.6)合金,用XRD,SEM,HRTEM分析了铸态及快淬态合金的微观结构;用自动控制的Sieverts设备测试了合金的气态贮氢动力学性能,用程控电池测试仪测试了合金的电化学贮氢动力学.结果发现,快淬无La合金具有典型的纳米晶结构,而快淬含La合金显示了以非晶相为主的结构,表明La替代Mg提高Mg2Ni型合金的非晶形成能力.La替代Mg明显地改变Mg2Ni型合金的相组成.当La替代量x=0.4时,合金的主相改变为(La,Mg) Ni3+ LaMg3.合金的气态及电化学吸放氢动力学对La含量及快淬工艺敏感,La替代使合金的吸氢动力学降低,但适量的La替代可以明显改善合金的放氢动力学及高倍率放电能力.适当的快淬处理可以提高合金的气态及电化学贮氢动力学,但获得最佳贮氢动力学的快淬工艺与合金的成分密切相关.     

氢爆工艺及其对钕铁硼磁体性能的影响

文章介绍了钕铁硼合金薄带的氢爆反应原理、生产工艺、较传统工艺的优点及能够对其产生影响的因素。对比了氢爆工艺与传统工艺对磁体性能及结构的影响。阐述和分析了氢爆工艺和气流磨制粉工艺在目前钕铁硼磁体生产过程中的重要性。     

Controlling the Phase Composition,Structure, and Complex of Properties of the High-Modulus Titanium Alloy by Thermohydrogen Processing

The possibilities and efficiency of applying the thermohydrogen processing (THP) of the high-modulus Ti–8.7Al–1.5Zr–2.0Mo titanium alloy with an aluminum content exceeding the solubility limit in α-titanium are considered. Experimental data on the influence of hydrogen on the alloy phase composition and structure are acquired. Regularities of phase transformations in the hydrogen-containing alloy under various thermal impacts are analyzed. The phase diagram of the alloy–hydrogen system in the hydrogen concentration range from the initial one to 1.0 wt % and the temperature range from 20 to 1100°C is constructed. It is shown that a single-phased β-structure is fixed with the concentration of introduced hydrogen of 0.6 wt % and higher by means of quenching from the β-region. Hydrogen saturation up to 0.8–1.0% leads to the implementation of the β → δ shear hydride transformation during quenching from temperatures below 750°C, and to the partial eutectoid transformation of the β-phase under slow cooling. It is established that hydrogen extends the stability region of the β-phase, lowering the temperature of the β/(α + β) transition by 210°C (at 1.0% H), and increases the stability temperature of the α₂-phase by 50°C. The process flowsheets and THP modes forming two structural types—submicrocrystalline and bimodal—are developed and approved for alloy samples. The formation mechanisms of these structures during THP are analyzed and the mechanical properties of the alloy are determined. It is established that THP leads to an increase in strength and hardness when compared with the initial state. The THP forming the microcrystalline structure causes a decrease in plasticity characteristics at the maximal hardness.     

稀贵金属在氢气纯化中的应用

综述了国内外对含氢同位素（氕H，氘D，氚T）气体及其含其它杂质（e,N2,Ar)混合气的纯化处理以获得高纯（99.9999%以上）氢气的各种方法及它们的优缺点。重点介绍了长期以来使用稀贵金属钯银合金（Pd-Ag)体系的固态扩散膜技术的研究与发展，分析了目前使用的钯银合金膜技术的优势与不足，指出了利用耐熔金属Zr,Nb,Ta,V等对氢的高选择性和高渗透性。并结合金属钯对氢的催化化特性和抗氧化性，对耐熔金属加以表面改性以制备高选择渗氢膜的技术方法。从而获得高纯氢气的巨大应用前景。     

LaNi_(5-x)Al_x贮氢合金的研究

本研究用Ａｌ置换ＬａＮｉ５合金中的部分Ｎｉ，得到一系列ＬａＮｉ５－ｘＡｌｘ（ｘ＝０．１，０．３，０．５）贮氢合金。对这些合金的吸放氢热力学和动力学性能的实验研究表明，随着Ａｌ的加入及Ａｌ含量的增加，贮氢合金的平台氢压降低，吸氢量有所减少，而吸放氢速度有所增加。通过对合金及其氢化物晶体结构的ＸＲＤ分析，发现Ａｌ的加入并未使晶体结构类型发生变化，只是晶格常数变大；ＬａＮｉ５－ｘＡｌｘ合金吸氢后原晶体结构也未发生变化，但其晶格常数增加较大。     

Study on Degradation and Recovery of AB5—Type Hydrogen Storage Alloy Used in Ni—MH Batteries

Ｎｉｃｋｅｌ ｍｅｔａｌｈｙｄｒｉｄｅ (Ｎｉ ＭＨ )ｂａｔｔｅｒｙｈａｓｂｅｅｎｕｓｅｄｉｎｍｏｂｉｌｅｅｌｅｃｔｒｉｃｆａｃｉｌｉｔｉｅｓｓｉｎｃｅｉｔｓｃｏｍｍｅｒｃｉａｌｉｚａｔｉｏｎ .ＲｅｃｅｎｔｌｙＮｉ ＭＨｂａｔｔｅｒｙｈａｓａｌｓｏｂｅｅｎｄｅｖｅｌｏｐｅｄａｎｄｕｓｅｄｉｎｔｈｅａｒｅａｏｆｅｌｅｃｔｒｉｃｖｅｈｉｃｌｅｓ[1～ 3 ] .ＡｌａｒｇｅａｍｏｕｎｔｏｆｖａｌｕａｂｌｅｒａｗｍａｔｅｒｉａｌｓａｒｅｎｅｅｄｅｄｉｎｍａｋｉｎｇＮｉ ＭＨｂａｔｔｅｒｉｅｓ .Ｐｒｏｖｉｄｅｄｔｈａ…     

氧氮氢碳硫在镍基高温合金锭中分布的研究

探讨杂质元素分布对避免缺陷产生和扩展意义重大,通过解剖整个镍基高温合金锭,探索氧、氮、氢、碳和硫在镍基合金锭中的分布。解剖方式为横向切片取样为主,沿锭边纵向抽取4mm×4mm细条为辅。横向切5个圆饼,每片制出约56个单样;纵向2根棒,每根棒切出80个单样。数据采集使用基于红外和热导检测原理的氧、氮、氢、碳、硫分析仪器,准确性有保障。实验结果显示:氧、氮、氢、碳沿锭纵向分布较均匀,仅锭芯部例外。其横向分布偏析严重,越靠近中心部位,氧、氮、氢、碳偏析越严重,氧和氢甚至可超出一个数量级范围以上。碳也不例外,在合金锭中心孔洞区域,通过金相显微镜可以观察到微小碳化物颗粒沿缩孔边缘处聚集析出。氮偏析不太严重,硫的横向、纵向分布均匀,未见偏析。     

氧氮氢碳硫在镍基高温合金锭中分布的研究

探讨杂质元素分布对避免缺陷产生和扩展意义重大,通过解剖整个镍基高温合金锭,探索氧、氮、氢、碳和硫在镍基合金锭中的分布。解剖方式为横向切片取样为主,沿锭边纵向抽取4mm×4mm细条为辅。横向切5个圆饼,每片制出约56个单样;纵向2根棒,每根棒切出80个单样。数据采集使用基于红外和热导检测原理的氧、氮、氢、碳、硫分析仪器,准确性有保障。实验结果显示:氧、氮、氢、碳沿锭纵向分布较均匀,仅锭芯部例外。其横向分布偏析严重,越靠近中心部位,氧、氮、氢、碳偏析越严重,氧和氢甚至可超出一个数量级范围以上。碳也不例外,在合金锭中心孔洞区域,通过金相显微镜可以观察到微小碳化物颗粒沿缩孔边缘处聚集析出。氮偏析不太严重,硫的横向、纵向分布均匀,未见偏析。     

CO/CO2气氛下Fe-C合金气固反应脱碳

 为研究Ar-CO-CO₂气氛下Fe-C合金薄带的脱碳效果,通过热力学分析结合试验,确定脱碳气氛条件混合气体流量为850 mL/min,CO的体积分数为25%,PCO₂/(PCO+PCO₂)为0.26。以初始碳质量分数为4.2%左右的Fe-C合金薄带为研究对象,探索不同脱碳温度、薄带厚度、脱碳时间对脱碳效果的影响。研究结果表明,对厚度为2 mm的Fe-C合金薄带,脱碳温度分别为1 293、1 353、1 413 K,脱碳60 min后,平均碳质量分数分别为2.748%、1.870%、1.134%。厚度分别为1、1.5、2 mm的Fe-C合金薄带,脱碳温度为1 413 K,脱碳时间为60 min,对应的碳质量分数分别为0.32%、0.92%、1.05%。证明提高脱碳温度、延长脱碳时间、减少薄带厚度均有助于提高脱碳效果。     

Effect of a microstructure and surface hydrogen alloying of a VT6 alloy on diffusion welding

The effect of a structural type (lamellar, fine, gradient) and additional surface alloying with hydrogen on the diffusion bonding of titanium alloy VT6 samples is studied. It is shown that the surface alloying of VT6 alloy parts with hydrogen allows one to decrease the diffusion welding temperature by 50–100°C, to obtain high-quality pore-free bonding, and to remove the “structural” boundary between materials to be welded that usually forms during welding of titanium alloys with a lamellar structure.     

热处理对贮氢合金电化学性能的影响

研究了热处理工艺氢合金活化性能,初始放电容量,稳定放电容量,电压平台及循环寿命等电化学性能的影响,并确定了合适的热处理工艺。     

粉末温轧工艺对W-20Cu合金密度和显微组织的影响

在W-Cu混合粉末中加入0.1%~2.0%(质量分数)的有机添加剂,在60~150℃温度下温轧成生板坯,然后进行液相烧结,获得W-20Cu合金板材。通过正交试验研究粉末轧制速度、轧制温度与添加剂含量对生板坯密度的影响,并对烧结板材的密度和显微组织进行分析与表征。结果表明,轧制温度与添加剂含量对粉末轧制板坯密度有显著影响,二轧制速度对生板坯密度的影响较小。随轧制温度升高,W-20Cu生板坯的密度增大,烧结板材的孔隙尺寸逐渐减小,孔隙率逐渐降低,烧结密度相应提高;随添加剂含量增加,板坯密度先升高后降低。在轧制温度为150℃,添加剂含量为0.3%时,生板坯的相对密度达到最大值85.38%,液相烧结后获得相对密度为99.65%的W-20Cu合金板材,金属Cu元素在钨基体中均匀、弥散分布。     

天然气制氢技术及其在合金工业中的应用

介绍天然气制氢工艺原理及过程,结合合金工业对氢气品质的要求,从理论和相关行业的应用实例阐述天然气制氢替代传统水电解制氢的可行性,从经济效益和社会效益两方面说明有必要大力推广天然气制氢技术在合金工业中的应用。     

Features of compacting hydrogen-doped granules of a VT5-1kt titanium alloy

The effect of hydrogen on consolidation of granules of the VT5-1kt alloy, as well as the structure, mechanical characteristics, and fracture micromechanism of a compact produced by the hot-isostatic-pressing technique, is studied. It is established that hydrogen doping allows obtainment of a compact of the VT5-1kt alloy of 100% density with a high complex of properties in the course of a few minutes at such temperature-strength conditions in which the consolidation of granules is not realized. It is shown that the process of consolidation of hydrogenated granules proceeds more effectively in the (α + β) region.     

钒基固溶体型贮氢合金的研究进展

金属钒具有吸氢量大、抗粉化性能好等优点，但是有效吸氢量较低，只有一半的氢能够释放出来，没有实用价值。在V-Ti二元合金的基础上形成的三元合金V-Ti-M(M代表Cr，Mn，Fe，Ni等)具有良好的贮氢性能。Ti／Cr比对V-Ti-Cr合金性能影响很大，Ti/Cr比值为0．75时V-Ti-Cr合金具有最大的贮氢量和有效吸氢量，同时热处理可以有效地提高V-Ti-Cr合金的有效吸氢量，并降低V的使用量。添加Mn的三元合金具有BCC和Laves相双相结构。V-Ti-Fe合金的贮氢量很高，并有希望利用便宜的钒铁做钒源。此外，V基固溶体合金还可以用于镍氢电池负极，如V-Ti-Ni合金具有很高的放电容量，目前需要解决其循环稳定性差和成本高的问题。     

Effect of additional hydrogen alloying on the formation of the phase composition and structure of a Ti-8.3Al-2.1Mo-2.2Zr-0.2Si titanium alloy

The effect of additional hydrogen alloying on the formation of the phase composition and structure of a titanium alloy with a high aluminum content is studied. It is shown that an α₂ + β structure can be developed under certain temperature-concentration conditions. The phase composition-hydrogen concentration-hydrogenation annealing temperature diagram has been constructed. It shows a change in the phase composition of a Ti-8.3Al-2.1Mo-2.2Zr-0.2Si alloy as a function of the hydrogenation annealing temperature and the hydrogen content after cooling to a normal temperature at a rate higher than the first critical rate.     

机械合金化Mg-Ni二元系储氢合金的研究

分析了Mg Ni二元合金研究的理论和现实意义。指出机械合金化是提高Mg Ni二元合金储氢性能的有效制备方法 ,并重点分析了球磨方式对合金结构及其储氢性能的影响。对目前研究较多的Mg Ni二元合金及其储氢性能分别进行了介绍