开孔泡沫铝的压缩与吸能性的研究

对渗流法制备的开孔结构泡沫铝进行准静态压缩实验, 测试了其压缩应力-应变曲线, 研究了开孔泡沫铝的准静态压缩力学行为及其吸能性。实验结果表明:开孔泡沫铝的压缩过程具有明显的三阶段变形特征, 即弹性段、塑性平台段和压实段, 并且在塑性段呈现出明显的应变强化现象;随泡沫铝孔径的增加, 屈服强度上升, 泡沫铝的吸能量上升而吸能效率却随孔径增大而基本保持不变。     

基体对泡沫铝压缩行为与吸能性的影响

研究以工业纯铝、高强度铝镁合金及高含锌量脆性铝锌合金为基体的泡沫铝压缩行为。结果表明，基体性能对泡沫铝的压缩行为和吸能性有显著影响。不同基体性质泡沫铝的压缩过程均出现三个明显的变形区域，但变形行为不同。以高塑性工业纯铝为基体的泡沫铝表现出典型塑性泡沫特征和较低坍塌屈服强度，高强度脆性基体的铝锌泡沫呈现典型的脆性泡沫特征和较高弹性模量及屈服强度，相同应变量的吸能量和吸能效率均明显高于另外两种泡沫铝。     

泡沫铝的单向压缩行为及其吸能性

在SUNS电子万能材料试验机上对国产工业用泡沫铝材料进行准静态单向压缩试验，分析试件尺寸、材料相对密度及泡孔尺寸对材料静态压缩性能及吸能性能的影响。结果表明，在准静态条件下，泡沫铝泡孔孔径越大，弹性模量与塑性模量越小、屈服强度越大．但当相对密度超过32％后，塑性压垮强度却因泡孔孔径增大而降低，弹性模量在相对密度约为30％时出现拐点。孔径大吸能效率高。试件高度减小，压缩应力-应变曲线中的塑性平台长度缩短，且当试件高度小于10mm肘，塑性压垮强度明显提高。理想吸能效率最大值随试件高度增加而提高。泡沫铝微结构中的微缺陷引起材料压缩性能的降低。     

镀铜碳纤维增强铝基泡沫材料准静态压缩力学性能及吸能特性

采用熔体发泡法制备镀铜碳纤维增强铝基泡沫材料,研究泡沫铝试样准静态压缩力学性能及吸能特性。结果表明,铝/碳纤维复合泡沫材料的平台应力随相对密度的增加而增大,碳纤维含量越高,平台应力增大的速度越快,试样最大的屈服强度可达9.51 MPa。密度对试样吸能效率和平台段吸能量同样有影响,对于相同碳纤维含量的试样,密度越大,能量效率峰值对应的应变值越小,单位体积泡沫铝在平台段的吸能量越高,增加碳纤维含量,会使吸能量随密度增加而升高的趋势变得更加明显。     

通孔泡沫铝合金的动态压缩力学性能研究

采用MTS810.23型万能材料试验机和分离式Hopkinson压杆(SHPB）设备对加压渗流法制备的通孔泡沫铝合金进行了不同应变率下的准静态和动态压缩试验，以研究通孔泡沫铝的动态力学性能。得出了通孔泡沫铝合金的压绵应力-应变曲线。结果表明，不同应变率下的压缩σ-ε曲线均分为线弹性、塑性变形和密实3个阶段。通孔泡沫铝合金表现出明显的应变率效应，其屈服应力和流动应力随应变率的提高而上升，动态压缩下．通孔泡沫铝的屈服应力随相对密度的增大而升高．且其比强度与相对密度的1．5次幂呈线性关系。     

镀铜碳纤维增强铝基泡沫材料准静态压缩力学性能及吸能特性研究

采用熔体发泡法制备了镀铜碳纤维增强铝基泡沫材料,并对泡沫铝试样开展了准静态压缩力学性能及吸能特性研究。结果表明,铝/碳纤维复合泡沫材料的平台应力随相对密度的增加而增大,碳纤维含量越高,平台应力增大的速度越快,试样最大的屈服强度可达9.51MPa。密度对试样吸能效率和平台段吸能量同样有影响,对于相同碳纤维含量的试样,密度越大,能量效率峰值对应的应变值越小,单位体积泡沫铝在平台段的吸能量越高,而增加碳纤维含量,会使吸能量随密度增加而升高的趋势变得更加明显。     

不同基体泡沫铝材料的吸能特性研究

对开孔泡沫铝、闭孔泡沫铝硅和闭孔泡沫铝铜材料进行了准静态压缩实验。研究了泡沫铝材料的准静态压缩力学行为及吸能机制,分析了相对密度和试件高度对泡沫铝吸能特性的影响。     

通孔泡沫铝合金的动态压缩力学性能研究

采用MTS810 2 3型万能材料试验机和分离式Hopkinson压杆 (SHPB)设备对加压渗流法制备的通孔泡沫铝合金进行了不同应变率下的准静态和动态压缩试验 ,以研究通孔泡沫铝的动态力学性能。得出了通孔泡沫铝合金的压缩应力 应变曲线。结果表明 ,不同应变率下的压缩σ ε曲线均分为线弹性、塑性变形和密实 3个阶段。通孔泡沫铝合金表现出明显的应变率效应 ,其屈服应力和流动应力随应变率的提高而上升。动态压缩下 ,通孔泡沫铝的屈服应力随相对密度的增大而升高 ,且其比强度与相对密度的 1 5次幂呈线性关系。     

Mg及TiH2添加量对熔体发泡法制备泡沫铝的性能影响

采用熔体发泡工艺,以TiH2作为发泡剂制备泡沫铝。研究了不同TiH2添加量和不同Mg添加量对铝熔体发泡效果的影响;并对泡沫铝试样的孔隙率和孔径进行测量。通过XRD对泡沫铝中物相进行分析,利用扫面电镜观测了孔隙的微观形貌。最后,对泡沫铝的压缩性能进行测试。结果表明：Mg能显著提高熔体发泡法制备泡沫铝的发泡效率和试样孔隙率,其最终主要以Al3Mg2和MgAl2O4等形式存在于泡沫铝中。当Mg和TiH2的添加量均为为1.5wt%时,制备的泡沫铝孔径均匀,压缩性能良好,且有较好的吸能能力。     

2024泡沫铝合金的制备方法与吸能性能

以尿素为造孔剂,采用填加造孔剂法制备了2024泡沫铝合金,并研究成型烧结温度、固溶时效时间对泡沫铝合金吸能性能的影响。结果表明,2024泡沫铝合金的最佳成型烧结温度为570℃,压缩屈服强度和平台应力值分别达到20.3 MPa和16.0 MPa,应变率为70%时体积比吸能值达到10.19 MJ/m3;时效时间的延长一定程度上提高了材料强度,但是牺牲了材料的韧性,经15 h时效的压缩屈服强度值达到峰值,吸能性能未得到提高。     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

Current situation and future trend of China rare earth luminescent materialindustry(continued)

<正>Developing ecological lighting source The world is facing the big problem of energy shortage today and the contradiction between economy development and environmental protection is worsened.Therefore,people are more likely to choose an ecological light source that is more energy efficient and environmental friendly.The choice provides great opportunity for the development of rare earth optical material industry in China.The concept of green lighting positions rare earth luminescent material as a leading player in illumination market.The light source of both rare earth luminescent lamp and LED lamp is ecological and energy saving.This is why     

Galaxy Magnets achieved the net profit of 34.02 million yuan in the first six months of 2014

正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets.     

Rare Earth Application in Steel in China

<正>China has rich rare earth resources.Output of rare earth and steel in China ranks the top first in the world.However,there is still certain distance between the steel produced in China and developed countries from the point of varieties and quality.China still has to import some types of steel.Improving the quality should be emphasiZed in future development of steel industry in China.Rare earth can be used to upgrade traditional steel     

China rare earth market review

正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow.     

稀散金属产业的观察与思考

分析了近年来国内外稀散金属产业的生产、应用、资源与市场状况.铟锡氧化物靶材、砷化镓晶片、锗红外材料、铼高温合金和硒在电解锰及玻璃的应用等已成为稀散金属的主要应用领域.稀散金属的产量快速增长达到历史高位而导致了市场的失衡.以GaInP_2/GaAs/Ge,CIGS和CdTe为代表的非硅系太阳能电池是稀散金属的新兴应用领域,将给稀散金属带来日益增长的需求.     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

2014 second batch of rare earth quota released

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