AZ31B镁合金薄板的钨极氩弧焊组织与性能研究

探讨了2 mm厚的AZ31B镁合金钨极交流氩弧焊焊接的工艺特点, 利用金相显微镜、X射线衍射仪、万能拉伸试验机、扫描电子显微镜等手段对焊接接头显微组织、焊缝相组成、接头力学性能、断口形貌特征等进行了分析。结果表明: 焊接电流为50 A时,外观成型良好, 焊缝质量高, 内部几乎无气孔和裂纹等缺陷, 焊接接头的抗拉强度达到210 MPa, 约为母材强度的87%, 断裂发生在焊缝区, 表现为韧-脆混合断裂。 焊缝区组织呈细小的等轴晶, 主要存在α-Mg和Mg₁₇Al₁₂两种相, 热影响区组织较粗大。硬度测试结果显示, 焊缝区域的硬度高于母材。     

Gd对AZ81镁合金显微组织的影响

利用光学显微镜、电子扫描、X射线衍射分析方法研究Gd对AZ81镁合金显微组织的影响.结果表明,合金的显微组织主要由α-Mg基体、β-Mg_(17)Al_(12)相、Al_2Gd相组成.Gd的加入使β-Mg_(17)Al_(12)相显著减少,Gd含量较低时AZ81镁合金的晶粒得到细化、组织较为均匀.随Gd的增加,β-Mg_(17)Al_(12)相有粗化、偏聚的趋势.     

退火处理对AM80镁合金组织性能的影响

利用X射线衍射(XRD)、光学电子显微镜(OM)、扫描电子显微镜(SEM)、能谱分析(EDS)、硬度测试及拉伸实验等方法研究了不同退火工艺对AM80镁合金组织及性能的影响。结果表明,退火处理前后AM80镁合金均由α-Mg基体、Mg17Al12相、MgZn相组成。退火处理后,第二相主要以层片状析出。随着退火温度的升高,第二相完全析出的时间变短,随着退火时间的延长,第二相析出数量增多,直至完全析出。退火处理后,合金硬度、强度及延伸率大部分比铸态高。430℃退火6h后合金硬度为80.11HB,抗拉强度为167.02MPa,延伸率为2.68%,此退火工艺为最佳工艺。退火处理前后合金均为脆性断裂。     

AC61铸造镁合金中物相和显微组织分析

介绍了AC61铸造镁合金的显微组织,并利用光学显微镜和X射线衍射以及扫描电镜对其显微组织进行了分析.结果表明,AC61铸造镁合金是由α-Mg基体、共晶体以及弥散分布于晶内的细小析出相组成,是典型的铸造离异共晶体组织.α-Mg晶粒为粗大的等轴晶,粒径约为150 μm,共晶体由α-Mg与γ-Mg17Al12组成,沿晶界成不连续网状分布,而U-AlCuMg则弥散分布于晶体内部.     

Sn对正挤压Mg-Al-Sn-Zn-Y合金组织和力学性能的影响

在275~400 ℃对Mg-6Al-2Sn-0.5Zn-0.5Y和Mg-5Al-4Sn-0.5Zn-0.5Y合金正挤压,利用光学金相显微镜（OM）、X射线衍射仪（XRD）、扫描电子显微镜（SEM）分析显微组织,并测试了其室温拉伸性能。结果表明,铸态合金主要由α-Mg、β-Mg17Al12相和Mg2Sn相组成。Sn含量由2%增加到4%后,Mg2Sn相和离异共晶β-Mg17Al12相体积分数增加,层片状共晶β-Mg17Al12相体积分数减少。挤压温度相同时,Mg-5Al-4Sn-0.5Zn-0.5Y合金挤压试样力学性能均优于Mg-6Al-2Sn-0.5Zn-0.5Y合金,275 ℃挤压试样抗拉和屈服强度最高,分别为329.9和254.4 MPa。两种合金的室温拉伸断裂方式均为准解理断裂。Sn的添加可有效促进挤压过程中动态再结晶的形核,并抑制再结晶晶粒长大,从而同时提高挤压态合金的强度和塑性。     

AC61铸造镁合金中物相和显微组织分析

介绍了AC61铸造镁合金的显微组织,并利用光学显微镜和X射线衍射以及扫描电镜对其显微组织进行了分析.结果表明,AC61铸造镁合金是由α-Mg基体、共晶体以及弥散分布于晶内的细小析出相组成,是典型的铸造离异共晶体组织.α-Mg晶粒为粗大的等轴晶,粒径约为150μm,共晶体由α-Mg与γ-Mg17Al12组成,沿晶界成不连续网状分布,而U-AlCuMg则弥散分布于晶体内部.     

焊接温度对Cu/Al瞬间液相扩散焊接头性能的影响

采用AC8B铝合金箔,在0.1 Pa真空度下,对Cu/Al异种金属进行瞬间液相扩散连接(Transient Liquid Phase,TLP),并研究了在不同焊接温度下接头区显微组织、不同区域元素的扩散迁移及接头力学性能。结果表明,Cu/Al TLP连接接头界面元素扩散明显,存在一定厚度的扩散层;铜铝两侧扩散层主要由Cu9Al4、Cu Al2金属间化合物组成,且随着焊接温度的变化,金属间化合物种类未发生改变。两侧扩散层的显微硬度明显高于基体母材,随着焊接温度的增加,接头剪切强度呈现出先上升而后下降的趋势,且在焊接温度为500℃时,接头剪切强度达到60.4 MPa。     

外加磁场对时效处理AZ91焊接接头组织和性能的影响

在AZ91镁板钨极氩弧焊(TIG)过程中,外加不同磁场电流纵向交流磁场,并在焊后进行时效处理,分析焊接接头时效处理后的组织和性能。结果表明,经时效处理后,焊缝中β-Mg17Al12相的连续网状被打散,呈较细小断续分布。随着磁场电流的增加,焊缝析出的第二相先变得细小断续后又变得粗大,焊接接头的显微硬度、拉伸强度和塑性先增大后减小,焊缝耐电化学腐蚀性先减小后增大。当磁场电流为1.5 A时,晶粒最为细小,大量的第二相呈断续、细小状分布,接头力学性能最好,而耐蚀性最差。     

焊接温度对AZ31B/Cu瞬间液相扩散焊接头组织及力学性能的影响

以Al为中间层对AZ31B/Cu异种材料进行瞬间液相扩散连接试验, 采用SEM观察接头界面扩散区的组织形貌, 结合EDS、XRD分析界面区的物相及成分, 采用室温拉伸实验机测试接头剪切强度, 研究了焊接温度对AZ31B/Al/Cu界面组织和剪切强度的影响。结果表明, 加热温度对Al、Mg、Cu元素扩散影响很大, 从而对微观组织和剪切强度产生影响。445 ℃时, Al、Mg元素扩散不充分, Mg/Al界面无法形成共晶液相, 界面结合较弱。450 ℃时, Al箔完全溶解, 界面区宽度显著增加, 从Mg侧到Cu侧, 扩散区的微观组织依次为α-Mg(Al)固溶体、Mg-Al共晶组织、Cu(Al)固溶体, 接头强度最高达到53 MPa, 约为母材AZ31B剪切强度的33.2%。460 ℃时, 界面扩散区宽度缓慢增大, 靠近Cu侧的界面区产生大量脆性Al-Cu化合物, 接头强度下降。     

工艺参数对AE44雷达外壳压铸件组织及力学性能的影响

采用正交试验研究了工艺参数对AE44镁合金雷达外壳压铸件力学性能的影响,分别研究了浇注温度、模具温度及压射速率对雷达外壳力学性能和显微组织的影响.试验结果表明:当浇注温度680℃、模具温度200℃、压射速率3.5m/s时,雷达外壳压铸件力学性能及组织最佳.对在最佳参数条件下制备的外壳本体试样进行物相分析可知,AE44合金主要由α-Mg基体和沿晶界分布的Mg-RE化合物组成,其中Mg-RE化合物主要为Al2RE相和Al11RE3相.对在最佳参数下制备的外壳压铸件的力学性能进行分析得出,其σb=245MPa,δ=5.48%,硬度为79.6HBS.     

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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