Synthesis of LaF3 superfine powder by microwave heating method

LaF3 superfine powder was synthesized from La(CH3COO)3 and NH4 F by microwave heating method,using ethanol or pure water as dispersants respectively. The results of XRD and SEM indicate that the superfine powder has high purity, regular particle shape and narrow distribution of granularity. The granularity of the best sample is in the range of 100 -200 nm. The influence of different dispersants on the crystal degree and microstructure was discussed. After the superfine powder was formed into a slice at pressure of 25 - 60 MPa, its electrochemical impedance spectroscopy was tested by electrochemical impedance spectroscopy (EIS) measurement. The result shows that the grain refining of LaF3 powder increases its ionic conductivity. Compared with traditional preparation methods of LaF3 powder, the advantages of microwave heating method were summarized.     

超低碳针状铁素体管线钢的显微特征及强韧性行为

利用力学实验及微观分析手段，研究了超低碳针状铁素体管线钢的显微特征及其对强韧性的影响。结果表明，通过纯净化和热加工工艺优化。可在超低碳管线钢中获得具有以针状铁素体为主的显微组织，并在其铁素体晶界上发现有马氏体薄膜的存在。这些微观特征成为大幅度提高超低碳针状铁素体管线钢强韧性的重要因素。     

400MPa级超级钢不同焊接方法焊接接头组织性能分析

采用手工电弧焊，二氧化碳气体保护焊，等离子弧焊焊接400MPa级超级钢，并对焊接接头显微组织及力学性能作了分析研究，结果表明，实际生产中可以应用二氧化碳气体保护焊焊接400MPa级超细晶粒钢。     

Crystallization process in rapidly solidified AI-Nd-Ni amorphous alloy prepared by melt spinning

Rapidly solidified ribbons of Al90Nd7Ni3 metallic glasses were prepared by using melt spinning. Crystallization process of the totally amorphous ribbons was investigated by differential scanning calorimetry and X-ray diffraction analysis, under continuous heating regime. The results show that, under continuous heating regime, the metallic glass devitrifies via two main stages: primary crystallization, resulting in two-phase mixture of a(Al) plus residual amorphous phase, and secondary crystallization, corresponding to some inter-metallic phases appearing,successively including A111 Nds, Als Ni, and some unknown phases, in the AI amorphous/crystal matrix. Four peaks appear on the continuous heating DSC curves. Their peak temperatures are respectively 470.8, 570.8, 585.6, and 731.6 K at infinitesimal heating rate, and their activation energies of the respective phase transformation are 183.0,294.7, 232.5 and 269.1 kJ/mol. The values of Avrami exponent of the four reactions decrease with increasing relative transformation degree. At the earlier stage of phase transformation, the values of n are larger than 4, and at the later stage the values of n become close to some value from 0.5 to 2.0.     

纳米晶Fe72.8Cu1Nb1.7V1.5Mn0.5Si13.5B9软磁合金的磁性能

本文报道了高导磁纳米晶Fe72．8Cu1Nb1．7V1．5Mn0．5Si13．5B9合金的直流和交流磁性能水平，磁导率频散行为以及高频铁损行为，给出了描述高频区频散行为和铁损行为的近似表达式。     

Cu、Co元素对激光烧结CrFeNiAlSi高熵合金组织与性能的影响

采用Cr、Fe、Ni、Al、Cu、Co、Si纯金属粉末按照等摩尔比混合并压坯,激光自蔓延烧结制备CrFeNiAlSi、CrFeNiAlCuSi、CrFeNiAlCoSi高熵合金。利用OM、XRD、SEM、显微硬度计及磨粒磨损机等试验表征设备,分析了CrFeNiAlSi、CrFeNiAlCuSi、CrFeNiAlCoSi高熵合金的显微组织、物相及力学性能。结果表明:CrFeNiAlSi高熵合金主要由BCC相组成,为菊花状组织。在加入Cu、Co元素后,从单一的BCC相转化为BCC+FCC两种相共存,但仍以BCC相为主,CrFeNiAlCuSi高熵合金为菊花状+胞状组织,CrFeNiAlCoSi高熵合金为等轴晶组织。加入Cu、Co元素改变了CrFeNiAlSi高熵合金的形貌与性能,加入Cu元素后孔隙减少,硬度下降,磨损率上升。加入Co元素后硬度上升,磨损率下降,显微硬度均值为1010 HV0. 1,磨损率最小为46 mg·cm~(-2)。     

植根焊接界 服务全行业——中国电器工业协会电焊机分会介绍

中国电器工业协会电焊机分会是由全国电焊机生产企业及其相关行业的企事业单位，依法自愿参加而组建，不受部门、地区和所有制限制，不以盈利为目的的社会团体、行业性组织。分会现有会员单位111家，理事单位19家，会员单位的电焊机制造能力占全国电焊机行业60％以上。     

高强耐磨复杂铝黄铜研究

在生产HA164-5-4-2过程中，解决了Fe、Mn的熔化及均匀化、无缺陷铸锭的生产方法、管材直度控制等工艺关键问题。合金的熔点910、4℃，流点949．2℃，相变热焓114．6J／g；热加工性能优良；在高于550℃时其组织是β相，在低于550℃时其组织是α β相，耐磨颗粒是多元富铁相；力学性能分别为σb=796MPa，σ0.2=675MPa，δ5=20％，IIB=218。同时报道了不同热处理条件下组织和性能的关系。     

Ce对共晶Mg-Al合金组织的影响

模拟AZ9l镁合金半固态液相凝固后期的成分，分析了共晶成分镁铝合金添加不同含量的稀土元素Ce后，铸态显微结构的变化。结果表明：Ce的加入改变了合金的组织，增加了初晶α相的含量，细化了β相并减少了β相的含量。随着稀土Ce加入量的增加，在Ce的加入量为0．6％时，所得的组织最好；在Ce含量大于0．6％时，随着Ce加入量的增加，细化效果反而变差。     

超细硬质合金圆片刀毛坯生产工艺比较

本文就超细晶粒硬质合金圆片刀毛坯在两种不同生产工艺过程中常见的问题加以综述,并对圆片刀毛坯的不同生产工艺进行对比性研究,为生产高质量、高合格率的超细硬质合金产品提供了有力的依据。