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在铝镁合金熔炼过程中,因为镁的化学性质活泼,导致合金的氧化、烧损现象十分严重,不仅降低了合金中镁的收得率,而且造成了巨大的经济损失.为了达到阻燃目的,国内外经常采用熔剂法和气体保护法,而目前研究的热点是合金化阻燃法.研究了合金化阻燃法,建立了相应的动力学规律,并对温度因素的影响进行了分析,所得实验结论对生产实践具有一定的指导作用. 相似文献
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镁锂合金无铬植酸化学转化膜研究 总被引:3,自引:0,他引:3
为了提高镁锂合金的耐蚀性能,采用无毒植酸作为化学转化处理液对其进行表面处理.利用SEM和XRD对植酸转化膜的形貌及结构进行分析,测试结果表明植酸转化膜较均匀,并覆盖有白色不规则的花絮状颗粒.提出了镁锂合金在植酸转化处理液中的成膜机理,用开路电位时间曲线阐释化学转化成膜过程.通过极化曲线、析氢实验及点滴实验比较植酸转化膜与传统铬酸转化膜的性能.结果表明,与传统的铬酸化学转化相比,植酸转化后合金的腐蚀电位由初始的-1.65V提高至-1.40V,析氢速率也明显更小,说明植酸转化对改善镁锂合金的耐蚀性能更加有效. 相似文献
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《材料导报》2020,(Z1)
镁锂合金是目前最轻的金属结构材料,因其低密度、高比强度和高比刚度等突出优点,在航空航天、武器装备、汽车等领域具有广阔的应用前景。但是要实现超轻镁锂合金的大规模应用,必须解决其熔炼困难的问题。本工作对目前的铸造镁锂合金熔炼工艺进行研究,以Mg-8Li-3Al-3Zn-1Y为研究对象,采用SF_6气体保护浇铸空冷、覆盖剂表面保护炉冷、覆盖剂全面保护炉冷、覆盖剂+Ar气保护浇铸空冷和真空感应熔炼+Ar气保护浇铸炉冷五种熔炼工艺来制备镁锂合金,对比研究五种熔炼工艺制备镁锂合金的效果及力学性能分析,总结各种熔炼工艺的优缺点。本研究对获得完整、无缺陷、组织优化和高性能的铸造镁锂合金,以及优化镁锂合金的规模化生产和制备工艺,具有重要的指导和借鉴意义。 相似文献
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利用动态机械热分析仪研究了四种镁硅合金的阻尼性能.研究表明:铸造镁硅合金具有良好的阻尼性能.并且体现出有别于纯镁的新阻尼特征,铸造镁硅合金具有较纯镁在更大应变振幅范围内的弛豫型内耗.由于Mg2 Si对晶界的钉扎作用,界面阻尼峰出现在较纯镁更高的温度.少量钙的添加改善了Mg2 Si析出的形态,但对阻尼性能的影响似乎不明显. 相似文献
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Yonghua Xia Baoping Zhang Yin Wang Mingfang Qian Lin Geng 《Materials science & engineering. C, Materials for biological applications》2012,32(4):665-669
In this paper, the in-vitro cytotoxicity and the in-vivo compatibility of Mg–4.0Zn–0.2Ca alloy are studied. The cytotoxicity of Mg–4.0Zn–0.2Ca alloy is examined by MTT method on osteoblast cells. The in-vivo behavior of Mg–4.0Zn–0.2Ca alloy is investigated on rabbits. It has been found that Mg–4.0Zn–0.2Ca alloy extract has no cytotoxicity on osteoblast cells. Three months after in-vivo experiment, about 35–38% magnesium alloy implant has been degraded and a degradation layer which is composed of Ca, P, O and Mg has been formed on the magnesium alloy implants. Histological analysis showed that new bone is observed around magnesium implant without inflammation reaction. In-vitro and in-vivo test indicated that the Mg–4.0Zn–0.2Ca alloy has good biocompatibility. 相似文献
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对ME20M镁合金板料进行了热拉深成形性能实验与数值模拟.研究表明,ME20M镁板热拉深成形极限高度随实验参数的不同而不同,其塑性成形性能随温度的升高明显改善;数值模拟可以很好地预测不同实验参数下镁合金板料热拉深成形极限的高度.对热拉深成形件传力区部位进行金相实验得知,合理控制热拉深实验参数能保证镁合金塑性成形件微观组织,进而保证成形件质量. 相似文献
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目的 通过径向锻造工艺制备大尺寸镁合金棒料,并研究ZK60镁合金稳定变形区轴向截面边部位置的组织演变规律.方法 基于轴对称模型,利用数学解析方法建立不同压下率下的镁棒应变分量数学模型;使用弹塑性有限元分析软件对不同压下率下的镁棒径锻过程进行热力耦合分析;采用GFM-SSP32径锻机对铸态ZK60镁合金棒材进行阶梯锻造实验.结果 随着径向压下量的增大,晶粒细化明显.当压下率达到62.29%时,孪生动态再结晶机制开动;与模拟结果相比,数学模型预测的平均相对误差约为8.4%,可较准确表征径锻镁棒的应变分布情况.结论 径向锻造工艺完全可以制备ZK60镁合金棒材,并可有效解决镁合金塑性变形过程中的易开裂、散热快等问题. 相似文献
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A new approach to improving the macrosegregation in zirconium‐containing magnesium‐lithium alloy 下载免费PDF全文
In the preparation process of zirconium‐containing magnesium alloy, although zirconium is introduced into alloy by magnesium‐zirconium master alloy, the settling of zirconium particles has always been a key problem. In this study, the magnesium‐30wt.%zirconium master alloy was added into magnesium‐14wt.%lithium‐zinc alloy melt in the form of the block (about 20 mm) and the particles (about 20 μm), respectively, and then magnesium‐14wt.%lithium‐zinc with 0.5 wt.% zirconium alloy were prepared using stir‐casting process. Macrosegregation of major element (zirconium), microstructure and microhardness at different casting positions were examined to investigate the effect of zirconium addition methods on macrosegregation of magnesium‐14wt.%lithium‐zinc alloy. The results show that, for the block magnesium‐zirconium master alloy addition, there is obvious macrosegregation in alloy ingots, the zirconium contents at the top position of ingot are higher than that at the bottom by nearly 200 %. The method of particles master alloy addition can effectively improve macrosegregation, the difference in zirconium contents between the top and bottom is less than 16 %. 相似文献
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Recent studies indicate that there is a high demand for designing magnesium alloys with adjustable corrosion rates and precipitation ability of bone-like apatite layer on the surface of magnesium alloys in body. An approach to this challenge might be the application of nanocomposites based on magnesium alloys. The aim of this work was fabrication and bio-corrosion evaluation of a nanocomposite that was made of magnesium alloy AZ91 as matrix and fluorapatite (FA) nano particles as reinforcement. Magnesium-fluorapatite nanocomposite (AZ91-20FA) was made via the blending-pressing-sintering method. In vitro corrosion measurements were performed for characterization of initial materials and produced composite. The results showed that the addition of FA nano particles to magnesium alloy as reinforcement can reduce the corrosion rate and accelerate the formation of bone-like apatite layer and in turn provide better protection for matrix alloy. It is suggested that the formation of bone-like apatite layer on the surface of magnesium alloy might contribute to the good osteoconductivity of magnesium alloys. 相似文献