热处理对汽车散热器用铝合金钎焊带材组织和性能的影响

研究了均匀化和非均匀化处理状态下的不同中间退火工艺对钎焊带材组织和性能的影响。结果表明：在钎焊带芯材3003铝合金铸锭没有均匀化处理时,采用低温再结晶退火,合金的晶粒较大且大小不一;高温快速加热退火,可获得相对细小、均匀的合金晶粒组织。热轧复合前对3003铝合金铸锭进行均匀化热处理,可获得均匀的合金组织和稳定的力学性能。     

冷轧工序对铸轧3003铝合金显微组织和性能的影响

文章研究了冷轧工序对铸轧3003铝合金显微组织和力学性能的影响。结果表明,改善冷轧工艺,在冷轧低道次后进行退火处理而非铸轧后直接退火有利于晶粒等轴均匀化,提高3003铝合金力学性能,成品退火后抗拉强度达到98MPa,延伸率达到49%,使得n值与r值较大,具有较好的拉延性能和冲压性能。     

3003铝合金均匀化退火状态下晶粒度的影响因素

在不同的加工率、温度、时间和升温速率条件下,研究3003铝合金均匀化退火状态的晶粒度影响因素。结果表明：在均匀化退火过程中升温速率对晶粒度的影响较大,在大卷的工业化生产过程中此问题较难避免,可通过成品厚度优化退火前加工率、退火温度和退火时间达到细化晶粒的目的,满足部分晶粒度要求相对较低的深冲料产品,实现部分铸轧供坯方式替代热轧供坯方式的生产要求。     

1100铝合金成品退火工艺优化研究

1100铝合金成品退火用时较长,生产效率低。通过四次工业试验,在确保铝卷料温偏差在10℃以内的前提下,提高升温段炉气温度,缩短退火时间,最终制定了2 h/380℃/10 h+1 h/315℃/4 h+1 h/275℃/5 h的高温短时三段式退火工艺制度。两种退火工艺制度下材料的力学性能基本接近,但比原低温长时退火工艺缩短退火时间4 h,生产效率得到大幅提升。     

均匀化退火对铸轧3003高深冲铝板带组织性能的影响

针对铸轧3003合金铝板带产品深冲性能方面的不足,实验使用铸轧供坯3003铝合金带材,通过两种不同的生产实验方案,在冷轧轧制前对坯料进行520℃～540℃及560℃～580℃均匀化退火,对均匀化退火前后的产品显微组织、力学性能等试验指标分析,验证不同均匀化退火温度对产品金相组织以及冲压力学性能的影响。结果表明,铸轧坯料在560℃～580℃均匀化退火作用下过饱和固溶体大量析出细小均匀的第二相,成品的晶粒组织更加细小均匀,有利于提高材料的的加工性能,同时通过本实验顺利打通了产品批量工业化生产最终工艺路线。     

轧制驱动ECA大应变加工及后续热处理对5052铝合金力学性能与晶体取向的影响

采用轧制驱动等通道转角(ECA)大应变技术对退火态5052铝合金进行大应变加工,并对大应变5052铝合金分别进行后续200℃×1 h,350℃×1 h,500℃×1 h的热处理,研究了大应变加工及后续热处理对5052铝合金的硬度、拉伸性能和晶体取向的影响。结果表明,轧制驱动等通道转角大应变技术可以显著提高5052铝合金的硬度与强度,尤其是屈服强度从107上升到275 MPa,硬度从HV60.7~HV115.6,提升幅度高达90%;后续200℃×1 h退火后合金发生一定程度的回复,硬度小幅下降(从HV115.6下降到HV105.8);后续350℃×1 h和500℃×1 h退火使合金的硬度与拉伸性能明显下降,材料发生明显再结晶现象,500℃×1 h退火后合金的力学性能回复到原始状态,但织构强度显著降低,晶体处于无择优取向状态。本文说明轧制驱动等通道转角大应变技术结合后续热处理可以有效调整合金晶体取向,但退火温度超过250℃后材料力学性能难以保证;对于纯铝来说,ECA加工后的后续热处理温度为250℃时,能够获得良好的力学性能和组织均匀性。     

热处理对电弧喷涂用CuNiIn丝材性能的影响

采用真空熔炼+热挤压拉拔的方法制备了电弧喷涂用Cu35Ni5In丝材,研究了铸锭均匀化退火、中间退火和成品退火温度对合金性能的影响,采用SEM、XRD以及金相等对退火后的合金组织进行了分析表征,采用万能试验机对中间退火后的丝杆进行了抗拉强度测试.结果 表明,CuNiIn铸锭采用1000℃×2 h的退火工艺显著改善了组织...     

铸轧3003深冲料用铝合金退火工艺研究

采用光学显微镜(OM)和拉伸试验机对铸轧法生产的3003铝合金深冲料成品退火工艺的显微组织和力学性能进行了研究,结果表明,两种工艺方案下生产的3003铝合金沿轧制方向0°的力学性能优于沿轧制方向90°,此差异性随退火温度升高而逐渐减小并趋于一致.铝合金样品经退火处理后的强度急剧降低,变化最大的温度区间处于280～300...     

制锁用H65黄铜带材深冲性能的研究

晶粒的大小、均匀性及取向决定着带材深冲性能,其受到加工率、退火温度、原始晶粒大小等因素的影响。可采用多轧程轧制和退火的方法生产制锁用H65黄铜带材,均匀分配加工率,采用中轧加工率55%、中间退火工艺460℃~520℃×8h,有利于带材深冲性能的良性遗传;采用精轧加工率50%、成品退火温度680℃,晶粒度控制在20~25μm,充分均匀晶粒和优化结晶取向,可提高带材深冲性能避免深冲破裂。     

双金属层状复合铸锭热处理研究

以复合铸造技术制备的4045/3003铝合金复合铸锭为研究对象,研究了均匀化温度和时间对界面处组织性能的影响。结果表明,经过均匀化退火后,共晶相熔断并球化,且在一定范围内,随着温度升高、时间增加,球化更完全,分布更均匀,但不能改变整体上共晶相的树枝状分布。均匀化后复合铸锭硬度和界面抗拉强度整体均略有提高。4045/3003铝合金复合铸锭最佳均匀化制度为560℃+12h。     

论从实践理解世界的物质性和自然世界的先在性

马克思主义唯物论是一种物本主义形态的唯物论,还是一种超越物本主义形态、从实践理解世界的本质相关问题的实践的唯物主义的唯物论?这是一个我们必须搞清楚的有关马克思主义唯物论的本质规定性和精神实质的重大问题.在考察物本主义的唯物论及其思维方式的局限性的基础上,揭示了马克思主义唯物论是现代的、实践的唯物主义,并重点研讨了马克思主义唯物论关于从实践理解世界的物质性和自然世界的先在性的原理,以期为马克思主义唯物论进一步阐明人类世界的实践性原理奠定基础.     

Effect of cyproheptadine on the ultrastructure of the neurons of the arcuate nucleus in the hypothalamus of the rat

The data are presented on changes in the rat arcuate nuclear neuron ultrastructure after using cyproheptadine (peritol, Egyt Pharmaceutical Works, Hungary) in a water suspension at a dose of 20 mg/kg once daily during 7 successive days and twice a day within 10 days. It was shown that cyproheptadine decreases the functional activity of the arcuate nuclear neurons, depending on the total amount of the drug used. Cyproheptadine-induced inhibition of the forming neurohormone release from neurons is likely to be one of the mechanisms of its therapeutic effect in Itsenko-Cushing's disease.     

Characteristics of the sympathetic innervation of the nictitating membrane and of the vasculature of the nose and tongue of the cat

Vasomotor responses from the nasal mucosa and tongue, and contractions of the nictitating membrane, were recorded on stimulation of the cervical sympathetic or internal carotid nerves. Preganglionic sympathetic nerve fibres which elicited a membrane response possessed a lower threshold than those which evoked nasal vasoconstriction, while the latter displayed a lower threshold than fibres which evoked tongue vasoconstriction. The sympathetic vasodilator fibres to the tongue whose activity was revealed after alpha-receptor blockade, had a similar threshold to the vasoconstrictor fibres. Membrane contraction, nasal vasoconstriction and occasionally tongue vasoconstriction could be evoked by stimulating the internal carotid nerve. The postganglionic fibres innervating the nasal mucosa had a similar threshold to those of the nictitating membrane, which may indicate that there are small myelinated fibres innervating the mucosa. The preganglionic compound nerve action potential had four major components, S1-S4. S1, S2 and usually S3 fibres were associated with membrane contraction; S2, S3 and sometimes S1 fibres were associated with nasal vasoconstriction; and S3, usually S2 and occasionally S1 fibres were associated with vasoconstriction in the tongue. It is concluded that each of these three groups of nerve fibres, but not S4 fibres, may include fibres associated functionally with the three effectors. There was a considerable difference between the relative amplitude of the responses of the three effectors elicited by stimulation of the cervical sympathetic nerve at frequencies between 0.2 and 2 Hz. Vasoconstrictor responses were relatively larger than membrane contractions suggesting differences in the mechanisms of neurotransmission at the neuroeffector junctions.