微量B对Mg-3Al-1Zn镁合金组织和性能的影响

B通过Al-3B中间合金加入Mg-3Al-1Zn合金中,利用OM、XRD及力学性能测试、极化曲线测定等手段对不同B加入量合金的组织和性能进行了分析.实验结果表明,合金的组织随着B加入量的增加变得粗大,当B加入量为0.05%时出现粗大枝晶,0.1%时枝晶进一步长大且出现二次枝晶.合金的力学性能和耐腐蚀性能也随B加入量的增加而降低.     

Al-5Ti-1B细化剂对ADC12铝合金铸态组织及性能影响

采用光学显微镜(OM)、扫描电镜(SEM)及力学性能测试等手段研究了Al-5Ti-1B细化剂对ADC12铝合金的显微组织及力学性能的影响.结果 表明:当Al-5Ti-1B加入量(质量分数,下同)小于0.2％时,初生α-Al枝晶发达且粗大、是典型的树枝状;当加入0.2％的Al-5Ti-1B时,合金铸态的晶粒细化效果最佳,...     

Al-5Ti-1B和Al-P中间合金对Al-Si合金的联合变质作用

研究了Al-5Ti-1B和Al-P中间合金对Al-Si活塞合金组织和性能的影响。结果表明，加入0．2％Al-5Ti-1B中间合金能使经Al-P中间合金变质过的ZL109合金的共晶团和初晶硅进一步细化，抗拉强度也明显提高。随着Al-5Ti-1B加入的增加这种细化作用逐渐减小，当Al-5Ti-1B的加入量为2％时甚至使ZL109中的初晶硅变粗，抗拉强度也随之降低。     

Yb和Al-Ti-B复合变质对过共晶Al-Si铸造合金组织和性能的影响

采用光学显微镜、扫描电子显微镜、电子探针,研究了不同比例的稀土Yb和Al-5Ti-B复合变质剂对过共晶Al-20Si合金显微组织与性能的影响。结果表明,Al-20Si合金中添加0.5% Yb和0.3% Al-5Ti-1B复合变质剂使得粗大的多边形状、块状和五瓣星状初生Si变质为细小块状,共晶Si由粗大的片状或针状结构变质为细小颗粒或者纤维结构,而且粗大的α-Al枝晶被细化为等轴枝晶。然而,当Al-5Ti-B变质剂含量达到0.4%时,初生Si和共晶Si出现粗化现象。力学性能测试结果表明,合金的抗拉强度和延伸率分别增加了83.7%和92.1%。     

硼对Mg-7Al-0.4Zn-0.2Mn合金组织及性能的影响

研究了B对Mg-7Al-0．4Zn-0．2Mn合金显微组织和力学性能的影响。结果表明：加入微量的B就能使合金的晶粒得到显著的细化，并且随着B加入量的增加，细化效果越明显，当B的加入量（质量分数，下同）为0．15％时，平均晶粒尺寸由未变质合金的约140μm细化到约40μm。分析认为：具有密排六方结构的高熔点化合物AIB2可作为α-Mg的异质核心，从而细化镁合金晶粒。微量B的加入使铸态合金的力学性能得到不同程度的提高，当B的加入量为0．15％时，合金的显微硬度、抗拉强度和屈服强度分别比未变质合金提高13．1％、19．5％和22．0％，冲击吸收功约为未变质合金的2．3倍。B的加入量为0．10％时，合金的伸长率比未变质合金提高21．6％，     

Sr+B联合熔体处理对Al-Si-Mg合金组织和力学性能的影响

考察了A1—lB中间合金对0．030％Sr变质的A1—11．6％Si0．4％Mg合金组织和力学性能的影响。发现A1—B中间合金在近共晶铸造A1—Si合金中具有优异的枝晶细化能力。通过比较3种不同熔体处理条件下(末变质 未枝晶细化处理、0．030％Sr变质处理、0．030％Sr 0．028％B联合熔体处理)合金铸态和T6状态下的力学性能并对断口形貌进行分析，可以得出在近共晶铸造A1—Si合金中同时加入Sr，B进行枝晶细化和共晶Si变质联合处理是十分必要的。     

Al-10Sr和Al-5Ti-0.2C对ZL101合金组织的影响

在ZL101合金熔体中分别或同时添加不同量的Al-10Sr和Al-5Ti-0．2C，保温不同时间，利用光学显微镜和电镜扫描，研究了Al-10Sr，Al-5Ti-0．2C对ZL101合金组织的影响规律。试验结果表明，向ZL101合金中添加质量分数为0．5％的Al-10Sr，可使共晶Si从粗大的针、片状转变为细小的短纤维状，同时促进了α-Al枝晶的形核生长，晶粒尺寸在100-250μm之间。若添加质量分数为0．2％的Al-5Ti-0．2C，可使初生α-Al晶粒成为40-70μm的等轴晶，对共晶Si也有一定的变质作用。当同时加入Al-10Sr和Al-5Ti-0．2C时，α-Al枝晶和共晶Si同时得到细化和变质，这主要归功于Al-10Sr和Al-5Ti-0．2C对ZL101合金细化变质的交互作用。     

Yb和Al-Ti-B复合变质对过共晶Al-Si铸造合金组织和性能的影响（英文）

采用光学显微镜、扫描电子显微镜、电子探针研究了不同比例的稀土Yb和Al-5Ti-B复合变质剂对过共晶Al-20Si合金显微组织与性能的影响。结果表明,Al-20Si合金中添加质量分数0.5%Yb和0.3%Al-5Ti-1B复合变质剂使得粗大的多边形状、块状和五瓣星状初生Si变质为细小块状,共晶Si由粗大的片状或针状结构变质为细小颗粒或者纤维结构,而且粗大的α-Al枝晶被细化为等轴枝晶。然而,当Al-5Ti-B变质剂含量达到0.4%时,初生Si和共晶Si出现粗化现象。力学性能测试结果表明,联合添加0.5%Yb和0.3%Al-5Ti-B后,合金的抗拉强度和延伸率分别增加了83.7%和92.1%。     

Al-5Ti-1B对铸造702A铝合金组织和性能的影响

铝合金的晶粒大小对合金的力学性能有着显著的影响.本研究采用性能稳定的Al-5Ti-1B合金细化剂对702A铝合金进行细化处理,对比细化剂的不同含量对铸造702A铝合金的微观组织和力学性能的影响.结果表明,在Al-5Ti-1B含量为0.15％时,合金细化剂在细化a枝晶的同时,共晶Si相也得到细化;其力学性能随着细化剂含量的增加,抗拉强度呈上升趋势,综合力学性能得到提高.     

微量Sc元素对Al-Cu合金组织与性能的影响

采用拉伸力学性能测试、扫描电镜与能谱分析等方法，研究了不同量稀土元素Sc对Al-4Cu合金组织与性能的影响。结果表明：稀土元素Sc能够细化Al-4Cu合金的晶粒组织，改善枝晶网胞；当Sc含量小于0．2％时，Al-4Cu合金的抗拉强度δb和屈服强度δ0.2提高约20MPa；当Sc含量为0．3％～0．4％时，抗拉强度δb和屈服强度δ0.2有所降低；当Sc含量为0．5％时，抗拉强度δb和屈服强度δ0.2又有所升高，但低于未添加Sc的Al-4Cu合金；Sc对合金的伸长率几乎没有影响。微量Sc元素添加到Al-4Cu合金中，当Sc含量小于0．2％时，基本上以固溶的形式溶入合金基体中；当Sc含量为0．3％。0．5％时，除部分固溶于Al基体中外，大部分形成起强化作用的Al3Sc相及交互作用AlCuSc相，AlCuSc相是Al-Cu-Sc系合金中的有害相，它使合金的力学性能在一定程度上有所降低。     

Effect of addition of Si on microstructure,mechanical properties,bio-corrosion and cytotoxicity of Mg-6Al-1Zn alloy

The Mg-6Al-4Zn alloy was fabricated by mechanical alloying (MA) and hot pressing to serve as biodegradable metal implant. The influence of addition of 1% Si (mass fraction) on the microstructure, mechanical properties and bio-corrosion behavior of Mg-6Al-1Zn alloy was studied using X-ray diffractometry, transmission electron microscopy, compression test, as well as immersion, electrochemical test and MTT assay. The results showed that the addition of 1% Si to Mg-6Al-1Zn alloy led to the formation of fine Mg₂Si phase with polygonal shape, and increased compressive strength, elongation and improved corrosion resistance. Furthermore, the cell viability of Saos-2 cells has been improved by addition of 1% Si to Mg-6Al-1Zn alloy. According to the results, the magnesium ions released in the methylthiazol tetrazolium (MTT) test have not shown any cell toxicity. All these indicated that the addition of 1% Si improved the properties of Mg-6Al-4Zn alloy for using as a biodegradable implant.     

Fluidity,Microstructure, and Tensile Properties of Sub-rapidly Solidified Mg-6Al-4Zn-xSn(x=0,0.6,1.2,1.8) Alloy

In this paper, the infl uence of the Sn element on the melt viscosity, grain size, shrinkage, and tensile properties of the subrapidly solidified Mg-6Al-4Zn alloy was studied. The results showed that the melt viscosity of the Mg-6Al-4Zn alloy was greatly decreased because of the addition of Sn. As the content of Sn increased from 0 to 1.8 wt.%, the grain size of the alloy was refined, and the dendrite microstructure was changed to rose-shaped ones simultaneously. The decreased melt viscosity and refined microstructure were conductive to the feeding of melt, which contributed to the reduction in volume fraction of shrinkage. The volume fraction of shrinkage of the Mg-6Al-4Zn-1.2 Sn alloy was reduced by 30.8%, compared with that of the alloy without Sn addition. Tensile properties of the Mg-6Al-4Zn-x Sn alloys were increased firstly and then decreased with the augmented Sn content. The yield strength, ultimate tensile strength, and elongation of the alloy containing 1.2 wt.% Sn were 21.4%, 39.5%, and 259.0% higher than those of the alloy without Sn addition, respectively. The addition of Sn was considered to reduce the shrinkage of the sub-rapidly solidified Mg-6Al-4Zn magnesium alloy and thus improved its tensile properties. To identify the mechanism, the effect of Sn on the volume fraction of shrinkage was discussed from three aspects of melt viscosity, grain refinement, and volume fraction of eutectic phases.     

Influence of yttrium on microstructure and mechanical properties of as-cast Mg-5Li-3Al-2Zn alloy

The influence of Y on microstructure and mechanical properties of as-cast Mg-5Li-3Al-2Zn alloy was investigated. The results show that the phase compositions of Mg-5Li-3Al-2Zn consist of α-Mg and AlLi phases. Adding Y to the alloy results in the formation of Al₂Y compound and facilitates grain refinement. The addition of 0.8 wt.% Y produces the smallest grain size. The tensile tests performed at room temperature show that the additions of Y can improve the mechanical properties of the alloy; the tensile strength and ductility reach peak values when the Y additions are 0.8 wt.% and 1.2 wt.%, respectively. The mechanisms of improvement are related to grain refinement and compound strengthening effects.     

稀土钇对铸态Mg-8Li-3Al-3Zn合金显微组织和力学性能的影响

镁锂(Mg-Li)合金是现今最轻的金属结构材料,在航空航天及交通运输等领域具有重大的应用价值.但铸造镁锂合金绝对强度低限制了其发展和应用.在Mg-Li二元合金中添加铝(Al)、锌(Zn)和稀土元素钇(Y)三种强化元素制备Mg-Li-Al-Zn-Y五元铸态镁锂合金来提高镁锂合金的力学性能.利用X射线衍射仪(XRD)、扫描...     

Effect of Cu addition on microstructure and properties of Mg-10Zn-5Al-0.1Sb high zinc magnesium alloy

To improve the strength,hardness and heat resistance of Mg-Zn based alloys,the effects of Cu addition on the as-cast microstructure and mechanical properties of Mg-10Zn-5Al-0.1Sb high zinc magnesium alloy were investigated by means of Brinell hardness measurement,scanning electron microscopy (SEM),energy dispersive spectroscopy (EDS),XRD and tensile tests at room and elevated temperatures.The results show that the microstructure of as-cast Mg-10Zn-5Al-0.1Sb alloy is composed of α-Mg,t-Mg32(Al,Zn)49,φ-Al2Mg5Zn2 and Mg3Sb2 phases.The morphologies of these phases in the Cu-containing alloys change from semi-continuous long strip to black herringbone as well as particle-like shapes with increasing Cu content.When the addition of Cu is over 1.0wt.%,the formation of a new thermally-stable Mg2Cu phase can be observed.The Brinell hardness,room temperature and elevated temperature strengths firstly increase and then decrease as the Cu content increases.Among the Cu-containing alloys,the alloy with the addition of 2.0wt.% Cu exhibits the optimum mechanical properties.Its hardness and strengths at room and elevated temperatures are 79.35 HB,190MPa and 160MPa,which are increased by 9.65%,21.1% and 14.3%,respectively compared with those of the Cu-free one.After T6 heat treatment,the strengths at room and elevated temperatures are improved by 20% and 10%,respectively compared with those of the as-cast alloy.This research results provide a new way for strengthening of magnesium alloys at room and elevated temperatures,and a method of producing thermally-stable Mg-10Zn-5Al based high zinc magnesium alloys.     

Effect of Ce-rich rare earth on microstructure and mechanical properties of Mg-10Zn-5Al-0.1Sb magnesium alloy

To improve the comprehensive mechanical properties of Mg-10Zn-5Al-0.1Sb magnesium alloy,different amount of Ce-rich rare earth(RE)was added to the alloy,and the effect of RE addition on the microstructure and mechanical properties of Mg-10Zn-5Al-0.1Sb alloy was investigated by means of Brinell hardness measurement, scanning electron microscopy(SEM),energy dispersive spectroscope(EDS)and X-ray diffraction(XRD).The results show that an appropriate amount of Ce-rich rare earth addition can make the Al4Ce phase particles and CeSb phase disperse more evenly in the alloy.These phases refine the alloy’s matrix and make the secondary phases[?-Mg 32 (Al,Zn)49 phase and?-Al 2 Mg5Zn2 phase]finer and more dispersive,therefore significantly improve the mechanical properties of the Mg-10Zn-5Al-0.1Sb alloy.When the RE addition is 1.0 wt.%,the tensile strengths of the alloy both at room temperature and 150oC reach the maximum values while the impact toughness is slightly lower than that of the matrix alloy.The hardness increases with the increase of RE addition.     

Sn对Mg-6Al-1.2Y-0.9Nd镁合金组织和性能的影响

采用XRD、OM、SEM和EDS等手段研究Sn对Mg-6Al-1.2Y-0.9Nd合金微观组织和力学性能的影响。结果表明, Sn可以显著提高合金从室温到175 ℃区间的抗拉强度,当Sn含量为1%时,镁合金在室温和175 ℃时抗拉强度达到最大值,分别为242和192 MPa,合全的拉伸断口为具有塑性特征的准解理断裂。 Sn的加入使合金的显微组织得到明显细化,并出现高熔点Mg2Sn合金相。合金力学性能的提高主要是由于细晶强化、弥散强化和固溶强化。     

挤压态Mg-6Zn-xEr合金的微观结构和力学性能

研究铸态、挤压态和挤压峰值态的Mg-6Zn-xEr合金的微观组织和力学性能。结果表明,Er的加入可显著改善Mg-6Zn合金的力学性能,经过峰值时效后合金的力学性能得到进一步提高;挤压态Mg-6Zn-0．5Er合金经过峰值时效处理后具有最佳的拉伸强度。该合金的抗拉强度和屈服强度分别为329MPa和183MPa,伸长率为12％。这表明添加0．5％Er可显著提高Mg-6Zn合金的时效硬化行为。挤压峰值态Mg-6Zn-0．5Er合金较好的力学性能归因于结构的细化和β1相的析出强化。     

Ce和Sb及时效处理对Mg-Zn-Al系铸造镁合金组织的影响

利用SEM、X射线衍射等手段研究了微量元素Ce和Sb及时效处理对Mg-Al-Zn系铸造合金组织和性能的影响。结果表明:Ce和Sb元素显著地细化了试验合金铸态组织,改善β相形貌及分布,并形成呈粒状弥散分布Mg3Sb2、Al11Ce3、CeCu6的新相;Mg-10Zn-2Al-1Cu+0.5%(Ce+Sb)试验合金的时效沉淀过程中弥散析出粒状、杆状析出相(Mg32(Al,Zn)49、Mg32Al47Cu7、Mg3Zn2、Mg3Sb2、CeCu6等),且其析出相的形成、析出速度和长大速度等都远远小于AZ91D合金,显示较好的时效强化效应。     

Mg-8Zn-4Al-1Ca合金的时效微观组织(英文)

利用TEM和HRTEM研究Mg-8Zn-4Al-1Ca合金的时效微观组织。结果表明:Mg-8Zn-4Al-1Ca合金较Mg-8Zn-4A1合金时效硬度显著增高。Mg-8Zn-4Al-1Ca合金在160°C时效16 h,有大量的盘状Ca2Mg6Zn3相沉淀弥散析出,此外,合金的微观组织中还存在晶格畸变、蜂窝状的莫尔条纹、刃型位错及位错环;经48 h时效后合金中沉淀相为粗大的盘状沉淀相和细小、弥散的粒状沉淀相;经227 h时时效后后,其组织中存在大量MgZn2相和Ca2Mg6Zn3相。因此,在Mg-8Zn-4Al-1Ca时效160°C的合金中添加Ca元素能有效提高合金的时效硬度及促进MgZn2强化相的生成。