Effects of Cerium on Microstructures and Mechanical Properties of Zn-22%Al Vibration Damping Alloy

Effects of Cerium on Microstructures and Mechanical Properties of Zn-22%Al Vibration Damping Alloy     

稀土元素铈对镁合金AZ91D显微组织和力学性能的影响

利用光学显微镜、X射线衍射和扫描电镜等分析研究含铈镁合金AZ91D（0．25％Ce、0．7％Ce、0．95％Ce）的显微组织,并对其力学性能进行了测试,同时与不含铈镁合金AZ91D进行了比较。结果表明,加入一定量Ce后的镁合金AZ91D形成杆状化合物Al4Ce,被推移到生长界面,阻碍枝晶的自由生长,从而细化合金显微组织;Ce能提高镁合金AZ91D抗拉强度和硬度,而对其屈服强度和延伸率影响不大;加入0．7％Ce的AZ91D镁合金晶粒细化效果和综合力学性能比较理想。     

Effect of Cerium on Mechanical Properties and Morphology of ZZn4-1 Alloy

ＺＡａｌｌｏｙｓｂｅｌｏｎｇｔｏｃａｓｔｚｉｎｃａｌｌｏｙｆａｍｉｌｙｄｅｖｅｌｏｐｅｄｂｙＣａｎａｄｉａｎａｎｄＡｍｅｒｉｃａｎｒｅｓｅａｒｃｈｅｒｓｉｎｍｉｄ1970ｓ.ＺＡａｌｌｏｙｓａｒｅｏｆｇｏｏｄｃａｓｔｉｎｇａｎｄｐｒｏｃｅｓｓｉｎｇｐｒｏｐｅｒｔｉｅｓａｎｄａｒｅｗｉｄｅｌｙｕｓｅｄｉｎｄｉｆｆｅｒｅｎｔｆｉｅｌｄｓ[1].ＨｙｐｏｅｕｔｅｃｔｉｃＺＺｎ41ａｌｌｏｙ,ａｓａｎｉｍｐｏｒｔａｎｔｍｅｍｂｅｒｏｆＺＡａｌｌｏｙｆａｍｉｌｙ,ｉｓｏｆｇｏｏｄｃａｓｔａｂｉｌｉｔｙａｎｄｔｈｕｓｉ…     

钇对Ti-43Al-9V合金组织性能的影响

采用OM，XRD，SEM和TEM等测试方法，分析了稀土元素(Y)对Ti—43Al—9V合金显微组织以及力学形能的影响。实验结果表明，Ti—43Al—9V—0．3Y合金由γ相、α2相、B2相和YAl2相组成；添加稀土可以细化Ti—43Al—9V合金的晶粒尺寸，并促进细小的α2／γ层片形成以及细化粗大的α2／γ／B2层片。对TiAl合金力学性能测试表明，适量添加稀土Y(0．3％，原子分数)可明显改善合金的室温强度和塑性，但过量添加将会造成材料性能降低；断口分析表明过量添加稀土导致沿晶断裂比例增加将损害TiAl合金的性能。     

Effect of Yttrium and Cerium Addition on Microstructure and Mechanical Properties of AM50 Magnesium Alloy

To develop magnesium alloy with low cost, high strength and excellent elevated temperature properties, effect of Y and Ce addition on microstructure and mechanical properties of AM50 magnesium alloy was studied. Result showed that addition of small amount of Y and Ce to AM50 alloys resulted in refinement of microstructure. Owing to the improvement of microstructure, the mechanical properties of alloys at both ambient and elevated temperature were increased. AM50 alloy containing 0.6 % Ce-0.3 % Y （mass fraction） had good refinement effect and relatively ideal mechanical properties.     

TC4钛合金轧板的织构对动态力学性能影响

利用分离式Hopkinson压杆试验装置,对具有不同织构特征的TC4合金试样进行动态压缩试验,分析织构特征对钛合金轧板各方向动态力学性能的影响。结果表明,900℃轧制板材的主织构为{1219}<12391>±30°RD,织构强度为10.557,在φ1=15°时出现峰值,有一定的织构分散,其中晶面{1219}平行板材的轧面,与基面{0001}夹角26.6°,晶向由〈1010〉向〈6 331〉方向漫散;950℃轧板的主织构为{1219}〈5321〉±20°RD,织构类型与900℃轧板相似,但织构强度为6.387,相对900℃轧板较弱,晶向由〈7341〉向〈4311〉方向漫散,在φ1=35°出现峰值;1050℃轧制板材的主织构为{12 19}〈1010〉,织构比较集中,织构强度为15.333,晶向〈101-0〉平行板材的轧向,与c轴为90°夹角。950℃轧制的TC4板材,织构强度较弱,其轧向(RD)、横向(TD)、法向(ND)的动态流变应力和动态均匀塑性应变差别不明显。900℃和1050℃轧制的TC4板材,由于织构强度较高,轧板存在明显的各向异性:TD方向的动态流变应力最高,ND次之,RD最低;RD方向的动态均匀塑性应变最大,ND次之,TD最小。     

含Cu高熵合金的组织结构和力学性能分析

高熵合金（HEAs）是一种由5种或5种以上元素以接近等原子比的方式混合而成的一种新型合金。HEAs的概念为开发具有独特性能的先进材料提供了新的途径,这是传统的基于单一主导元素的微合金化方法无法实现的。由于Cu元素与HEAs中其他元素的混合焓均为正值,因而更容易偏聚形成富Cu的面心立方（fcc）结构。本文主要总结了合金成分、制备方法对含Cu HEAs组织结构的影响规律以及含Cu HEAs的热稳定性。例如Al的添加会使CoCrCuFeNi合金从fcc单相转变为fcc+bcc的双相结构,而Ni含量的增加则会将AlCoCrCuNi的多相组织转变为单相fcc结构。与传统铸造工艺相比,选区激光熔化和喷溅急冷等具有极高的冷却速度,限制了元素的扩散,因而制备而成的AlCoCuFeNi和AlCoCrCuFeNi合金均是bcc结构。组织结构的改变会进一步影响含Cu HEAs力学性能,因而本文也探讨了合金成分、制备工艺和服役温度与力学性能的关系。例如,V的添加可以提高合金的强度,以先进制备方法如选区激光熔化或激光粉末熔融得到的合金具有优于铸造合金的力学性能。     

Effect of Scandium and Zirconium on Mechanical and Exfoliation Corrosion Properties of Al-Mg-Mn Alloys

To quest for the best combination of mechanical properties and exfoliation corrosion resisting property of Al-Mg-Mn base alloys, and to seek after the effect of Sc and Zr on mechanical and exfoliation corrosion properties of Al-Mg-Mn alloys, comparative research technique was used, the mechanical properties of Al-Mg-Mn alloys with and without minor Sc and Zr treated by different annealing were measured, the degrees of exfoliation corrosion for these alloys through accelerated exfoliation corrosion test were evaluated, and polarization curves of these alloys were measured, too. The micro-morphologies of corrosion specimens were observed by SEM and the corrosion product was analyzed using EDS. Optical microscope and TEM were used, the relationship between their microstruc-tures and mechanical properties, exfoliation corrosion resisting property was investigated, and the results show that the addition of minor Sc and Zr can enhance the strength greatly and also improve the combination of strength and plasticity. Moreover, the addition of minor Sc, Zr does not cause appreciable decrease of exfoliation corrosion resisting property, the Al-Mg-Mn-Sc-Zr alloy annealed at 350 ℃ for 1 h has excellent combination of mechanical properties and exfoliation corrosion resisting property, the satisfied combination of mechanical properties nad exfoliation corrosion resisting property can be obtained by means of adding minor Sc and Zr, decreasing the content of Mn, and adopting reasonable annealing practice.     

Influence of Electric Field on Mechanical Properties of Al-Li Alloy Containing Cerium and Electronic Mechanism

Ｒｅｃｅｎｔｌｙ ,ｍａｎｙｍａｔｅｒｉａｌｒｅｓｅａｒｃｈｅｒｓｈａｖｅｃｏｍｅｔｏｒｅａｌｉｚｅｔｈａｔｔｈｅｅｌｅｃｔｒｏｎｉｃｃｈａｒａｃｔｅｒｈａｓａｄｅｃｉｓｉｏｎａｌｒｏｌｅｏｎｍａｔｅｒｉａｌｐｒｏｐｅｒｔｉｅｓａｎｄｍｉｃｒｏｓｔｒｕｃｔｕｒｅ[1～ 3] .Ｔｈｅｓｅｗｏｒｋｓｒｅｖｅａｌａｎｅｗｍｅｃｈａｎｉｓｍｔｏｍａｔｅｒｉａｌｂｅｈａｖｉｏｒａｎｄａｎｅｗｕｎ ｄｅｒｓｔａｎｄｉｎｇｅｌｅｃｔｒｏｎｔｈｅｏｒｙｏｆａｌｌｏｙ .Ａｄｄｉｔｉｏｎ ａｌｙ,ｔｈｅｅｆｆｅｃｔｏｆａｎｅ…     

Influences of Cerium and Carbide on Mechanical Properties of Steels

Ｉｔｗａｓｔｈｏｕｇｈｔｔｈａｔｔｈｅｒａｒｅｅａｒｔｈｓｗｅｒｅｎｏｔｃａｒｂｉｄｅｆｏｒｍｉｎｇｅｌｅｍｅｎｔｓｂａｓｅｄｏｎｔｈｅｆａｃｔｔｈａｔｔｈｅｒａｒｅｅａｒｔｈｓｒｅａｃｔｏｎｃａｒｂｏｎｉｎｓｔｅｅｌｓｉｍｉｌａｒｌｙｔｏｓｉｌｉｃｏｎ ,ｔｈｅｅｌｅｍｅｎｔｗｈｉｃｈｎｅｖｅｒｆｏｒｍｓｃａｒｂｉｄｅａｎｄｉｓｄｉｆｆｅｒｅｎｔｆｒｏｍｔｈｅｅｌｅ ｍｅｎｔｓｓｕｃｈａｓｃｈｒｏｍｉｕｍ ,ｍａｎｇａｎｅｓｅａｎｄｔｕｎｇ ｓｔｅｎｗｈｉｃｈｆｏｒｍｃａｒｂｉｄｅｓ .Ｍｏｒｅｏｖｅ…     

Study on microstructure and mechanical properties of ZL107 alloy added with yttrium

The effects of Y on the microstructure and mechanical properties of ZL107 alloy were investigated using optical microscope, scanning electron microscope (SEM), Brinell hardometer, and MTS 810-22M tensile testing machine in this paper. The results showed that after Y was added to ZL107 alloy, the size of α-Al dendritie reduced, the acicular eutectic Si became short rod-shaped or granular, and the number and size of the blowholes obviously reduced. The mechanical properties of ZL107 alloy firstly increased and then decreased with Y content increasing. When Y content was 0.1 wt.%, the tensile strength and hardness of the alloy were maximum.     

Effect of Heat Treatment on Mechanical Property of High Cr-W Cast Iron

The microstructure of high Cr-W cast iron after heat treatment were analyzed, and the effect of various heat treatment temperature and time on mechanical properties of high Cr-W cast iron were studied, and the best process parameter of heat treatment was provided in this paper. The results show that the heat treatment can improve the mechanical property of high Cr-W cast iron, and higher synthetic mechanical property of high Cr-W cast iron can be obtained when treated with normalization at 980℃ for 2h and tempered at 400℃ for 2h.     

Effect of Neodymium on As-Cast Microstructure and Mechanical Properties of AZ31 Wrought Alloy

Nd in the form of powder or intermediate alloy was added to AZ31 wrought alloy. The as-obtained alloy was characterized and tested with respect to its microstructure and mechanical properties. The relationship between the microstructure, mechanical properties and tensile fracture mechanism were discussed, with relevant alloys as reference for comparison. Experimental results show that the same quantity of Nd was added into AZ31 in powder form or in intermediate alloy, the absorption rate of Nd reached only 10.8% for the former case and as high as 95% for the later case. Pure Nd powder was added, no new compound was detected, but it served as reductant and purified alloy melt, resulting in improving the tensile strength while Nd was added into AZ31 as Mg-Nd intermediate alloy. The compound Al2Nd and Mg12 Nd were formed in magnesium alloy, which were distributed in the matrix in the shapes of strip and particle, evidently refined the as-cast structure. The as-cast tensile strength (228MPa) of adding pure Nd powder approximated to the figure (245MPa) of adding Mg-Nd intermediate alloy. The tensile fracture mchanism of as-cast AZ31 transformed from cleavage fracture into quasi-cleavage fracture.     

Effect of Impurities and Cerium on Stress Concentration Sensitivity of Al-Li Based Alloys

Ｔｈｅｒｅａｒｅａｌｗａｙｓｓｏｍｅｇｅｏｍｅｔｒｉｃａｌｄｉｓｃｏｎ ｔｉｎｕｉｔｉｅｓ ,ｓｕｃｈａｓｆａｓｔｅｎｅｒｈｏｌｅｓ ,ｆｉｌｌｅｔｓａｎｄｇｒａｖｅｓ ,ｉｎｐｒａｃｔｉｃａｌａｉｒｃｒａｆｔｃｏｎｓｔｒｕｃｔｉｏｎｃｏｍ ｐｏｎｅｎｔｓ .Ｉｎｔｈｅｖｉｅｗｏｆｍａｔｅｒｉａｌｍｅｃｈａｎｉｃｓ ,ｔｈｅｓｅｇｅｏｍｅｔｒｉｃａｌｄｉｓｃｏｎｔｉｎｕｉｔｉｅｓｃａｎｂｅｃｏｎ ｓｉｄｅｒｅｄａｓｎｏｔｃｈｅｓ .Ｓｔｒｅｓｓｃｏｎｃｅｎｔｒａｔｉｏｎｕｓｕａｌ ｌｙｏｃｃｕｒｓａｔｎｏｔｃｈ…     

Effect of Boron and Cerium on Microstructures and Properties of Cu-Fe-P Alloy

The effects of B and Ce on the removal of inclusions, microstructures, and properties of Cu-Fe-P alloys were studied. Certain impurity elements and the microstructures, mechanical properties, and conductivity of four experimental alloys, Cu-0.22Fe-0.06P, Cu-0.22Fe-0.06P-0.05Ce, Cu-0.22Fe-0.06P-0.02B, and Cu-0.22Fe-0.06P-0.05Ce-0. 02B （ %, mass fraction）, were tested and analyzed. Results show that on one hand, B and Ce have a remarkable function of removing S, Pb, and Bi from copper alloys ; on the other hand, the recrystallization temperature of the Cu-Fe-P alloy is considerably increased by adding trace B and Ce, resulting in the combined strengthening effect of precipitation hardening and cold work hardening after cold working and aging, while the negative effect of B and Ce on conductivity is slight. Therefore, a good combination of high strength and conductivity is achieved.     

稀土对Al—Mg—Si系合金组织性能影响的分析

以实验为基础研究了稀土对Al-Mg-Si系铝合金的组织及性能的影响,并从理论上分析了稀土的作用机理。结果表明,稀土对合金组织具有改善作用,同时对春性能也有影响。最后对实验结果进行了分析与总结。     

复合稀土银合金组织与性能的研究

制备了几种复合稀土银合金,实验研究了复合稀土银合金的组织与性能．提出复合稀土对银合金性能影响有互补性,复合稀土元素在铸态下偏聚且共生在枝晶边界上,形成AgrRE金属间化合物及氧化物,对银合金有显著的强化作用和细化晶粒作用,并提高了合金的再结晶温度,增强了合金的耐热性．这种合金经冷变形后退火,可以消除枝晶偏析,含稀土的第2相化合物呈团絮状分布在再结晶组织上,这有利于改善银合金的组织与性能．     

Preparation, Characterization and Antibacterial Property of Cerium Substituted Hydroxyapatite Nanoparticles

Nanoparticles of hydroxyapatite （HAP） and cerium substituted hydroxyapatite （CeHAP） with the atomic ratio of Ce/[ Ca ＋ Ce] （xco） from 0 to 0.2 were prepared by sol-gel-supercritical fluid drying （SCFD） method. The nanoparticles were characterized by TEM, XRD, and FT-IR, and the effects of cerium on crystal structure, crystallinity, and particle shape were discussed. With the tests of bacterial inhibition zone and antibacterial ratio, the antibacterial property of HAP and CeHAP nanoparticles on Escherichia coli, Staphylococcus aureus, Lactobacillus were researched. Results showed that the nanoparticles of HAP and CeHAP could be made by sol-gel-SCFD, cerium could partially substitute for calcium and enter the structure of HAP. After substitution, the crystallinity, the IR wavenumbers of bonds in CeHAP decreased gradually with increase of cerium substitution, and the morphology of the nanoparticles changed from the short rod-shaped HAP to the needle-shaped CeHAP. The nanoparticles of HAP and CeHAP with Xco below 0.08 had antibacterial property only forcibly contacting with the test bacteria at the test concentration of 0.1 g · mi^-1, however, the Ce- HAP nanoparticles had antibacterial ability at that concentration no matter statically or dynamically contacting with the test bacteria when Xco was above 0.08, and the antibacterial ability gets better with the increase Of Xce, indicating that the antibacterial property was improved after calcium was partially substituted by cerium. The improved antibacterial effects of CeHAP nanoparticle on Lactobacillus showed its potential ability to anticaries.     

稀土硅铁孕育对高铬合金白口铸铁性能的影响

本文对稀土硅铁、钒铁、钛铁的不同加入量对高铬合金白口铸铁性能的影响进行了实验研究。结果表明，当稀土硅铁的加入量为１．２～１．５％时，冲击韧性达到最大值，硬度也有提高。稀土硅铁孕育可以显著改善碳化物的形态和分布，细化基体组织。当加入量为０．９～１．５％时，大部分碳化物断网，呈孤立状态分布。钒铁的加入量为０．２％时，即可起到明显的孕育作用，机械性能得到提高。