Ultrahigh strength and improved electrical conductivity in an aging strengthened copper alloy processed by combination of equal channel angular pressing and thermomechanical treatment

In this paper,equal channel angular pressing and thermomechanical treatment was employed to improve the strength and electrical conductivity of an aging strengthened Cu-Ti-Cr-Mg alloy,and the microstructure and properties of the alloy were investigated in detail.The results showed that the samples deformed by the combination of cryogenic equal channel angular pressing(ECAP)and rolling had good comprehensive properties after aging at 400℃.The tensile strength of the peak-aged and over-aged samples was 1120 MPa and 940 MPa,with their corresponding electrical conductivity of 14.7%IACS and 22.1%IACS,respectively.ECAP and cryogenic rolling introduced high density dislocations,leading to the inhibition of the softening effects and refinement of the grains.After a long time aging at 400℃,the alloy exhibited ultra-high strength with obvious increasing electrical conductivity.The high strength was attributed to the synergistic effect of work hardening,grain refinement strengthening and precipitation strengthening.The precipitation of a large amount of Ti atoms from the matrix led to the high electrical conductivity of the over-aged sample.

Microstructure evolution of processed Mg-Al-Zn alloy by equal channel angular extrusion in semi-solid isothermal treatment

Microstructure evolution of processed Mg-Al-Zn alloy by equal channel angularextrusion(ECAE) in semi-solid isothermal treatment was investigated. The results show that withincreasing semi-solid isothermal treatment temperature, the a phase solid grain size of processedMg-Al-Zn alloy by ECAE increases firstly due to coarsening of a phase solid grains, then decreasesdue to melting of a phase solid grains. With the increase of extrusion passes during ECAE, the aphase solid grain size in the following semi-solid isothermal treatment decreases. The a phase solidgrain size of processed Mg-Al-Zn alloy by ECAE under route B_C is the smallest, while the a phasesolid grain size of processed material by ECAE under route A is the largest. The primary mechanismof spheroid formation depends on the melting of recrystallizing boundaries and diffusion of soluteatoms in the semi-solid state.

Tensile properties of 2024 Al alloy processed by enhanced solid-solution and equal-channel angular pressing

Equal-channel angular pressing(ECAP) of an enhanced solid-solution treated 2024 Al alloy was successfully performed at room temperature, with an imposed equivalent normal strain of about 0.5. A very high hardness about HV191 and yield strength about 610 MPa (30% higher than those of the unECAPed 2024 Al alloy) in terms of commercial aluminum alloys were observed for the ECAPed 2024 Al alloy. In addition to the strengthening, this process allows the ECAPed 2024 Al alloy have a moderate level of tensile ductility (about 12.7%) and a significant strain hardening capability up to tensile failure. After aged at 373 K for 48 h, the ECAPed alloy increases its hardness (about HV201) and tensile ductility (about 14 %) further. The TEM results show that the ECAPed 2024 Al alloy presents a plate structure (about 50-100 nm) with high density of dislocation and additional thin plate (approximately <10 nm= inside. The XRD results show that the ECAP processing decreases the texture and increases the dislocation density of the alloy considerably. The theoretical calculations show that the increase of dislocation density resulting from ECAP processing makes a considerable contribution about 55.2 % for the improvement of yield strength.

Influence of Equal Channel Angular Pressing on Tribological Properties of Low Carbon Steel (Fe-0,09C-0,64Si-,26Mn)

This paper presents the results of equal channel angular pressing (ECAP) and subsequent heat treatment (HT) as a method to improve the wear resistance of metallic materials in friction sliding. The effect of ECAP and HT on the microstructure and mechanical properties of low carbon steel is investigated in this work. The mechanisms of wear resistance of steel with ultrafine and nanostructures produced by equal-channel angular pressing is analyzed. The results show that ECAP at room temperature and annealing at 350&degC and 450&degC can be used as a technology of reducing wear in friction sliding.

Effect of Solution-ECAP-Aging Treatment on the Microstructure and Properties of TB8 Titanium Alloy

The microstructure and mechanical properties of the TB8 titanium alloy were controlled by a secondary processing technology of solution-equal channel angular pressing(ECAP)-aging treatment,which combined strong plastic deformation with heat treatment. The effects of ECAP and heat treatment on the microstructure and properties of the titanium alloy were systematically investigated by optical microscopy(OM), scanning electron microscopy(SEM), hardness tests, and tensile property analysis. The results indicate that the metallographic structure without ECAP treatment is mainly equiaxed β-phase, while that after ECAP treatment is equiaxed β-phase with grain fragmentation, slip bands, and new small grains. After 850 ℃ solutionECAP-520 ℃ aging treatment, the titanium alloy has the smallest grain size, while the directionality of tissue growth along the ECAP direction is the most apparent. Under the same solution-aging conditions, the hardness of the titanium alloy increases from 431.5 to 531.2 HV compared to that without ECAP treatment, i e, increases by 23.11%, and the tensile strength increases from 1 045.30 to 1 176.25 MPa, i e, increases by 12.5%.

ECAP变形及半固态等温处理对Al-25%Si合金组织和性能的影响

对铸态Al-25%Si合金进行等通道转角挤压(ECAP),并结合半固态等温处理技术,研究了ECAP挤压及半固态等温处理工艺参数对合金微观组织和室温拉伸性能的影响。利用光学显微镜观察分析微观组织,拉伸试验机测试室温拉伸性能,以及扫描电子显微镜分析断口形貌。研究结果表明,ECAP变形能够有效地细化Al-25%Si合金中的初生硅相,其平均直径由铸态的117.9μm降至31.9μm,同时形状因子也由0.12提升至0.40。ECAP后的常温力学性能也得到明显提升,其抗拉强度也由铸态的96 MPa提升至200 MPa,伸长率由1.04%提升至3.25%。在半固态加热过程中,初生硅的形状因子随等温温度的提升和时间的延长呈先增后降的趋势。在590℃保温10min,其形状因子最高为0.62。

台湾地区居民法律地位:三重面向、内容构造与优化路径

台湾地区居民法律地位问题,是防范与遏制“台独”分裂活动、推动两岸融合发展、推进国家完全统一进程中必须面对的重大现实问题。在法律实践中,台湾地区居民地位具有“待解放的中国人民”“特殊的中国公民”“同等待遇的中国居民”三重面向。相关立法坚持目标和问题导向,逐渐趋向具体化、同等化和常态化。当前,台湾地区居民法律地位的主要问题是如何推动落实同等待遇,这在一定程度上影响了其内容构造。其中,“居住地”标准是优化落实台湾地区居民法律地位的基础,权利义务是其规范内核,政策则对法律规定起着引领、实施和补充的重要作用。为切实提升台湾地区居民国家认同,建议接续推进身份管理模块化、推动同等待遇实质化、逐步实现权利义务体系化,形成优化台湾居民法律地位的系统方案。

Microstructural evolution of AZ61 magnesium alloy predeformed by ECAE during semisolid isothermal treatment

The microstructural evolution of AZ61 magnesium alloy predeformed by equal channel angular extrusion（ECAE） during semisolid isothermal treatment（SSIT） was investigated by means of optical metalloscopy and image analysis equipment.The process involved application of ECAE to as-cast alloy at 310 ℃ to induce strain prior to heating in the semisolid region for different time lengths.The results show that extrusion pass,isothermal temperature and processing route have an influence on microstructural evolution of predeformed AZ61 magnesium alloy during SSIT.With the increase of extrusion pass,the solid particle size is reduced gradually.When isothermal temperature increases from 530 ℃ to 560 ℃,the average particle size increases from 22 μm to 35 μm.When isothermal temperature is 575 ℃,the average particle size decreases.The particle size of microstructure of AZ61 magnesium alloy predeformed by ECAE at BC during SSIT is the finest.

温建民微创[足母]外翻病症诊疗体系学术思想及运用

[足母]外翻病症作为常见的前足疾病,其诊疗体系一直备受关注。该文介绍了温建民教授基于中医阴阳平衡和筋骨理论,结合现代手术经验,历经40余年的深入临床实践和研究,构建了以“阴阳平衡”“筋骨并重”“动静结合”“内外兼治”为原则的中西医结合微创治疗[足母]外翻病症诊疗体系(包括第一跖骨微创切骨手法整复术、“裹帘”外固定、围手术期中药的辨证应用以及中医的康复调护等四大关键技术),该体系为[足母]外翻病症的标准化微创治疗提供了系统指南,亦为中西医结合治疗其他骨伤科疾病提供了重要思路,具有极高的借鉴及推广价值,是温建民教授的重要科研成果及心血结晶。

ECAP和时效对Mg-4Zn-1Mn-0.5Ca合金组织和性能的影响

将铸态Mg-4Zn-1Mn-0.5Ca合金在300℃热挤压成棒材,对棒材进行180℃时效处理和200℃等通道转角挤压(ECAP)。研究了热挤压合金、ECAP 8道次合金和时效后ECAP 8道次合金的组织和性能。随后对试样进行室温和150℃低温单轴拉伸。结果表明:8道次ECAP后合金比热挤压态合金具有更细、更均匀的晶粒组织,同时提高了合金的室温屈服强度。时效后ECAP 8道次合金的150℃断裂伸长率比未时效ECAP8道次合金提高17.4%,说明时效处理对合金性能起着重要作用。

温建民教授中西医结合微创治疗拇外翻学术思想总结

阐述温建民教授中西医结合微创治疗拇外翻的学术思想。温老师治疗拇外翻的核心思想来源于中医的阴阳理论、筋骨理论及天人合一的整体观念,在此基础上凝练出“筋骨并重”“动静结合”及“内外兼治”3条治疗大法,涵盖了微创截骨手法整复、裹帘法外固定、中药内服外用、中西医结合康复调护4个操作环节。温老师传承经典,融贯中西,从中西医结合的角度贡献了“筋”与“骨”伤病的独家治疗经验和学术思想。

基于“筋骨并重”理论探析踝关节损伤的临床诊治

踝关节损伤是临床常见的骨科疾病之一,常常因足部受力不平衡使关节超出活动范围而诱发。踝关节是人体最主要的负重关节,是生活、运动、体育锻炼和军事训练中最常见的损伤,且复发率较高,属于中医学“筋伤”范畴,流行病学调查发现,其患病率正在呈逐渐上升趋势。踝关节损伤类疾病作为中医药治疗的优势病种,运用“筋骨并重”理论为指导,以“摇拔戳”手法促进筋骨关系恢复,“弃杖膏”外敷促进局部循环,针刺触发点加快损伤踝关节修复,配合康复锻炼可有效恢复关节功能,预防损伤发生。综合运用以上治疗方式可使患踝逐渐达到“筋柔骨正”“气血调和”的正常状态,避免了手术治疗的痛苦,同时还能有效地促进踝关节损伤患者的康复,提高患者生活质量。

《监狱法》修改的高度现代化监狱文明期待

在监狱法迎来三十年来第一次真正意义上的修改之时,社会对建成高度现代化监狱文明有着一种普遍期待。显然,监狱法修改应合理回应社会期待。由此,首先,收集专家评估和公众评估两个层面的调查问卷;其次,运用验证性因素方法,编制现代化监狱文明指数,对我国现代化监狱文明状况进行客观评估。再次,基于评估结论,提出建成高度现代化监狱文明的监狱法修改完善建议:其一,增设人格尊严基本原则、赋予服刑人员行政诉权,建设高度的服刑人员处遇文明;其二,监禁设施实现由数量型向质量型转变,建设高度现代化监禁设施文明;其三,增设比例原则、平等对待原则,建设高度现代化监狱执法文明;其四,增设“确保服刑人员释放后重新融入社会”,建设高度现代化监狱改造文明。

涉台营商环境的法理阐释与体系优化

涉台营商环境是以同等待遇为基础,以促进两岸融合发展为目标的综合性制度环境,具有政务、市场、法治、人文等不同构成要素。自1979年以来,涉台营商环境经历了从“招商引资”到“融合发展”的制度逻辑转型过程。在规范构造上,涉台营商环境通过法制供给、行政服务和司法保障三大领域,形成了一个开放性的整体环境。在坚持两岸融合发展的前提下,优化涉台营商环境可以从转变制度供给导向、构建公私合作治理、协调央地权责配置和实施立法评估制度等方面入手。

均压通风技术在采面回风隅角低氧治理中的应用

5203综采工作面受埋深较浅,同时采面采空区与上覆煤层采空区、地面漏风裂隙等存在漏风通道,导致5203综采工作面回采推进期间存在回风隅角CO浓度超标以及氧气浓度偏低等问题,制约采面安全生产。结合采面通风系统以及现场生产条件,提出将均压通风技术应用到采面回风隅角氧气浓度偏低治理中,通过采面与采空区间压力平衡,达到控制有害气体向回采空间涌入目的。依据现场情况,确定均压通风机型号以及均压通风设施布置情况。现场应用后,5203综采工作面回风隅角CO浓度偏高以及氧气浓度偏低等问题得以较好解决,可确保采面煤炭安全回采。

Microstructure and mechanical properties of fine grained uranium prepared by ECAP and subsequent intermediate heat treatment

The microstructure and mechanical properties of fine grained uranium prepared by equal channel angular pressing(ECAP)and subsequent intermediate heat treatment were investigated systematically by the confocal laser scanning microscope(CLSM),electron backscatter diffraction(EBSD)and split Hopkinson pressure bar(SHPB).The results show that the initial coarse grained uranium was refined from about 1000 to 6.5μm prepared by ECAP at 3 passes and subsequent heat treatment,and the corresponding dynamic yield strength increased from 135 to 390 MPa.For the ECAPed uranium samples,the relationship between grain size and yield strength could be described by classical Hall−Petch relationship,and the fitting Hall−Petch relationship for the fine grained uranium samples prepared by ECAP was drawn.

住院医师规范化培训招录问题分析及对策探讨

招收录取工作是住院医师规范化培训体系的重要关键环节,对于满足培训需求、保证培训质量具有重要意义。但在管理过程中,住院医师规范化培训招收工作的问题逐渐暴露出来,如一些专业招录生源数量少、偏远地区生源质量低、专业学位硕士研究生招生规模与住培容量不匹配等问题。2021年,国家颁布了《医师法》,并推出和实施"两个同等对待"重大政策,这一系列政策改变为住培质量建设提供了强大动能。在一系列利好政策的保障下,笔者提出保障住院医师合理待遇,精准定点组织专场住培招录宣讲活动,加强住培招录宣传网络和新媒体平台建设,创新录取机制等具体解决措施,吸引优秀生源,把好住培"入口"关,确保住培质量提升。

“被监禁”者的医疗权利:比较法视野下的罪犯医疗权

权利存在三个维度:就其理论维度言,医疗权是公民所普遍享有的基本权利;但其在实践面向罪犯医疗权时,却与普通公民医疗权存在显著差异——刑罚执行的封闭性与罪犯群体的刑事人类学特征限制了罪犯医疗权利的同等实现;而其在实定法上,尽管对罪犯医疗权的实现标准存在不同的表达,却都以排除权利阻碍为目标,以实现罪犯医疗权利的“同等国民待遇”为基本原则,且其中的权利同等性、获取同等性和效果同等性属于法定权利的典型实现标准,堪供我国监狱医疗的立法借鉴。

“筋骨并重”视阈下鸢尾素对肌骨衰减的异病同治作用

骨骼和骨骼肌通过多种渠道相互串扰,共同组成机体最大的生物运动组织——肌肉骨骼系统。鸢尾素是一种由运动介导的激素样肌因子,具有同时调节肌再生和骨稳态的双重功能。基于“筋骨并重”及“异病同治”理论,从中西医两个维度出发,深入探析鸢尾素对肌肉及骨骼衰减病变的双重治疗作用,以期为肌骨共病的基础研究和临床防治提供新导向。

杀虫、灭菌热湿平衡处理对实木地板坯料质量的影响

选择4种常用进口树种实木地板坯料和1种国产树种实木地板坯料,利用木材常规干燥试验机进行兼顾杀虫(D工艺)、灭菌(S工艺)的热湿平衡处理,检测分析其终含水率、厚度上的含水率偏差、残余应力、可见缺陷等指标变化。结果表明:地板坯料的质量在不同树种、同一批次内均存有差异。本研究中制定的D工艺(65℃/相对湿度73.8%~89.5%)、S工艺(75℃/相对湿度76.7%~91.2%)两个等级,可满足地板坯料杀虫、灭菌的加热技术要求,同时可降低地板坯料内和坯料间的最大含水率偏差,提高含水率均匀度,降低厚度上的含水率偏差,降低残余应力值,且对可见缺陷的影响不明显。热湿平衡处理坯料的质量符合LY/T2058—2022《实木地板坯料》或GB/T6491—2012《锯材干燥质量》中二级材的要求。