Effect of heat treatment on microstructure and properties of hot-extruded nickel-aluminum bronze

The effect of heat treatment on the microstructure and properties of a hot-extruded nickel-aluminum bronze was investigated. Experimental materials were heat treated through different processes, including quenching, normalizing, aging and annealing, and their microstructure, corrosion resistance and mechanical properties were characterized. It is found that quenching causes all β phase transformed into β phase, however, normalizing causes β phase transformed into β α and κ phases. When the quenched sample is aged, fine phase is precipitated from the as-quenched microstructure of β＇ phase. Annealing causes the transformation of β into a and κ phases. The results of mechanical property tests show that quenching, normalizing and aging improve the tensile strength and hardness of the experimental material, with a corresponding fall in elongation. Annealing raises the elongation but reduces the tensile strength and hardness. Furthermore, corrosion resistance of nickel-aluminum bronze ranks from worse to better in the following order： aged, quenched, normalized, hot-extruded and annealed. However, with the exposure time of corrosion test increasing, the difference of average corrosion rate between those nickel-aluminum bronzes tums small.     

向熔体深处引入高温气流精炼铝熔体

为了精炼铝合金,除掉其中的氢和非金属夹杂,广泛地采用了惰性和活性气体吹洗熔体的方法. 在具有高精炼能力的活性气体中,氯气和氯化物得到了最广泛的应用.文献指出,用氯气和惰性气体的混合物精炼铝合金,可将金属中的氢含量降低到0.1厘米~3/100克,氧化物降低到0.01%,这时的钠含量不超过0.0002～0.0003%.     

Microstructures and Plastic Anisotropy of As—Cast Low Carbon Steel Strips

对比研究了低碳钢带铸材不同处理状态钢带和薄板铸坯中不同位置切片的组织特征、晶体学织构和15％工程应变条件下的塑性异向性．结果表明，带铸材试样中存在{111}与{114}特征织构，织构强度均较弱；铸坯切片中存在{111}与{001}特征织构，并且因局部凝固冷速不同存在明显的织构强度差异．两组低碳钢的法向异向性与平均晶粒尺寸的对数之间尽管均存在线性关系，但斜率明显不同．分析表明法向异向性的晶粒尺寸依存性与钢带中织构的强弱有关，由此提出了“有效织构强度比”的概念，从塑性变形理论的角度解释了微观组织对塑性异向性的影响．     

Ti9Al合金的氢塑性效应

采用真空自耗电弧炉熔炼制备Ti9Al合金，通过渗氢处理显著提高氢含量，在凸轮塑性试验机ЧПИ-2上以10mm／min的速度进行热模拟试验。研究发现：氢可以降低Ti9Al合金的相变温度，扩大α β区的温度范围；氢作为卢稳定剂会妨碍或完全抑制以Ti3Al为基的α2相的析出；钛合金的氢合金化可促使卢相在更低温度下稳定化，明显地提高了Ti9Al合金塑性。     

真空炉低温区炉温均匀性探讨

真空炉低温区炉温均匀性探讨北京航空材料研究院（北京１０００９５）张善庆刘忠秋莫卫红北京华翔机电技术联合公司孙强１前言一般真空炉都在高于５００℃使用，主要用于淬火或高温回火。如何扩大真空炉的使用范围，使其能在低温下使用是真空热处理界非常关注的一个问题。...     

Effect of temperature on mechanical behavior of AZ31 magnesium alloy

Strain rate sensitivity and tension/compression asymmetry of AZ31 magnesium alloy at different temperatures and strainrates were investigated.Both of mechanical behaviors are temperature dependent.Strain rate sensitivity increases with increasingtemperature.Thermally activated slip is the source of strain rate sensitivity.At the temperature below or near 373 K,strain ratesensitivity is very little.Tension/compression asymmetry in yielding decreases with increasing temperature.Twinning is the reasonof tension/compression asymmetry.At the temperature above or near 573 K,the material shows little tension/compressionasymmetry of the flow stress.     

利用微波介电加热和微波干燥水解法制备TiO2微粒

利用微波介电加热和微波干燥条件下TiCl4直接水解的方法制备出平均尺寸为40m，粒径分布窄，均为球形且形态均一，团聚较少，金红石型的TiO2纳米粒子，其内部品粒平均大小为17nm。而传统加热和干燥条件下形成的纳米微粒平均为60nm，粒经大小不均一，形态较不规则，团聚严重。微波加热和干燥方法具有清洁、快速均匀高效、环境友好的优点，推广前景良好。TiCl4水解法经济便利，适于工业化生产。     

EDTA法测定石灰乳中活性CaO含量

本文针对石灰乳中活性CaO测定现有方法的严重缺陷,探讨了用EDTA法滴定石灰乳中已离解的Ca~(2-),取代用盐酸滴定OH,确定石灰乳中活性CaO的含量方法的可行性,比照石灰乳中活性CaO在氨碱法制碱生产中与各反应物的反应机理,对石灰乳中活性CaO作了重新定义,并对实际样品用两种方法分别进行了测定,进行了比较。本方法原理可靠,手续简单,能够满足生产控制分析的需要。     

改性聚丙烯酰胺水溶液的疏水缔合性质

合成了一种疏水缔合水溶性聚丙烯酰胺共聚物，使用荧光光谱法并结合紫外及流变性实验，对制备的疏水缔合水溶性聚丙烯酰胺共聚物在水溶液中形成疏水微区、超分子聚集体及空间网络结构进行了研究，并用扫描电子显微镜证实了溶液中网络结构的存在．     

新型农药——速杀畏在水稻残留量的测定

前言速杀畏是广西南宁化工厂于一九八二年从几种杀虫剂农药剂型中筛选出来的一种复合剂型,属高效、广谱性的有机磷杀虫剂。有良好的触杀、胃毒作用,并兼有内吸、熏蒸和杀卵作用,杀虫效果理想。速杀畏具有刺激性气味、易溶于水,药效稳定之特点。为测定其在水稻上的残留量,我们以南宁化工厂提供的样品,进行了分析测试,方法如下: