合金元素Mn对铝合金阳极组织与性能的影响

通过改变锰元素的含量(0%,0.5% ,0.8%,1.2%),观察Al-5%Zn-0.03%In-1%Mg-0.05%Ti-Mn合金的组织,测试合金的电化学性能,研究锰对该合金组织与电化学性能的影响.结果表明:适量的锰能细化铝合金的晶粒,减弱杂质铁的有害作用,改善溶解均匀性,保证了铝合金较好的电化学性能.含0.5% Mn的铝合金晶粒细小,有适量的析出相,电流效率达90.3%,电容量达2577 A·h/kg,且均匀溶解,具有比较好的综合性能.     

Effects of silicon,magnesium and strontium content on the qualities of Al-Si-Mg alloys

According to the specification of AA standard, the magnesium content of 356.1 alloy ranges from 0.25 to 0.45%. In producing Al-Si-Mg alloy the strontium content for the modified 356 (Al-7%Mg) alloy might range from 0.005 to 0.02%. Therefore, 356 alloys might be produced with different percentages of Mg and/or Sr. The effects of changes in Si content (from 6.6% to 10.8% in gravity casting and 6.5% to 10.3% in squeeze casting), Mg content (from 0.36% to 0.48% in gravity casting and 0.3% to 0.44% in squeeze casting), and Sr content (from 0.0007% to 0.0158% in gravity casting and 0.0015% to 0.04% in squeeze casting) on the microstructures, density, mechanical properties and strength of different Al-Si-Mg alloys were fully investigated and discussed. Different melts were poured in the ASTM B108 permanent mould and dies in a vertical squeeze machine to produce bar castings. These bar castings were then machined and the mechanical properties tested. Experimental results showed that if a high strength and a high elongation were desired in a squeeze casting after T6 treatment, an increase in Si and Sr content to 9.9% and 0.019% (Mg at 0.3%) would lead to 280 MPa strength, 12% elongation and Weibull modulus of 34 in reliability of strength. If both strength and reliability were desired in a squeeze casting after T6 treatment, an increase in Si content to 10.3% (Sr at 0.0015% and Mg at 0.3%) would result in 294 MPa strength, 8.7% elongation and a great Weibull modulus of 67. In gravity casting, after T6 treatment, increasing Si content to 10.4–10.55% and Sr content in the range of 0.0007–0.0208% and 0.35% Mg could develop 282–284 MPa strength at about 6.6% elongation with Weibull modulus of around 31. In Al-7Si-Mg alloy, increasing Mg content from 0.26% to 0.48% decreased the tested elongations of both as-cast and heat treated squeeze castings and gravity castings.     

阿司匹林、维拉帕米单用和合用对大鼠肠系膜微循环的影响1

目的 研究阿司匹林(Asp)与维拉帕米(Ver)合用对大鼠肠系膜微循环的影响。方法 右旋糖酐(Mr 480 000)360 mg·kg^-1 iv 制备大鼠肠系膜急性微循环障碍(AMD)模型, 采用活体微循环法观察肠系膜微循环细动, 静脉血流速度(ABFV、VBFV), 血流状态(BFS), 血管口径(AD、VD)的变化。结果 Asp 2.5、5 mg·kg^-1、Ver 0.3、0.6 mg·kg^-1,Asp+Ver(1+0.15)、(2.5 +0.3)mg·kg^-1 iv 可使ABFV 增大各为11.1 %、31.3 %、18.7 %、19.5 %、26.5 %、37.3 %; VBFV 则为12.5%、25.7 %、12.5 %、13.7 %、30%、34.7 %, BFS 改善;AD 增大4.3 %、17.9 %、31.5 %、35 %、20 %、38.1 %;VD 则为2.2%、4.2 %、25 %、31.5 %、5.8 %、23.5 %;CN 增多;Asp+Ver 可明显逆转AMD 。结论 Asp 增快ABFV、VBFV 作用优于Ver, 而Ve r 扩张AD、V D 作用强于Asp, 两者合用呈协同效应, 并对右旋糖酐诱导的AMD 具有拮抗作用。     

Effects of Si Content and the Addition Amount of Al-3B Master Alloy on the Solidification Structures of Hypoeutectic Al-Si Alloys

Al-Si based cast alloys have become morewidely used in atomobile and aerospace indus-try due to their excellent proPerties, such as highstrength to density ratios, high castability andmachinability and much attention has been fo-cused on this area. Since the discovery [l1 thatAl-4B master alloy could be used to refine A356alloy effectively this phenomenon has arousedmuch attenton and discussion among many in-vestigators [2--13]. Wth resPect to the role thatAl-B tyPe master alloy has played …     

微波场在冶金级硅酸浸提纯过程的应用

为了降低冶金级硅粉中金属杂质的含量,本文比较了微波场、球磨活化、恒温水浴等不同反应条件对冶金级硅中金属杂质去除效果的影响.实验结果表明,微波场作用下杂质Fe、Al、Ca、Ti的去除效率分别为83%,73%,93%,54%;球磨活化作用下杂质Fe、Al、Ca、Ti的去除最率分别为78%,69%,83%,46%;恒温水浴作用下Fe、Al、Ca、Ti的去除效率分别为72%,54%,67%,38%.微波场作用效果要明显优于球磨活化和恒温水浴作用,且微波场作用时间少干另外两者,探讨了微波场湿法提纯冶金级硅、球磨活化湿法提纯冶金级硅的原理.     

高温焊接对1.25Cr0.5Mo焊接构件疲劳寿命的影响

选取不同的温度(550,650,750,850℃)对1.25Cr0.5Mo钢进行高温焊接,在高温焊接及常温焊接后对焊件进行残余应力测试和疲劳试验.结果表明,550,650,750,850℃高温下焊接的试件,其焊缝热影响区的残余应力最大值(纵向、横向)比常温下焊接焊缝热影响区残余应力最大值(纵向、横向)都显著降低:纵向和横向降低幅度分为50.1%,48.9%;74.8%,67.4%;83.9%,79.4%;91%,89.7%.高温焊接试件的疲劳寿命的平均值比常温下焊接试件疲劳寿命的平均值分别提高31.02%,38.84%,47.23%和62.28%.结果表明,高温焊接能明显降低焊件的残余应力和提高焊件的疲劳寿命.     

聚苯胺对环氧涂层防腐蚀性能的影响

制备了本征态聚苯胺在涂层中质量分数分别为0%、1.5%、3%、5%、7%、10%的聚苯胺/环氧防腐蚀涂层,通过Tafel极化曲线和电化学阻抗谱测试对比了其在35%NaCl溶液中的腐蚀性能,结果表明,聚苯胺含量对涂层的防腐蚀性能有较大影响:涂层中聚苯胺含量较小时,随着其在涂层中含量的增加,涂层的腐蚀电位相应提高,而随着聚苯胺含量的进一步增加,涂层的防腐蚀效果开始下降.涂层中聚苯胺质量分数含量为5%时,涂层具有最佳的防腐蚀性能.     

熔模精密铸造工艺生产高强度铝合金大型铸件的实践

论述了如何解决某大型高强度铝合金铸件在生产实践中出现的问题,从合金熔炼工艺及热处理工艺等方面提出了改善铸件冶金质量及力学性能的措施,使该铸件冶金质量及力学性能大幅度提升,X光合格率由原来14％提高到90％,抗拉强度达到470 MPa以上的由原来20％提高到92％,伸长率达到3％以上的由原来10％提高到93％.     

注射用伏立康唑药物利用评价标准的建立和应用

目的: 建立注射用伏立康唑药物利用评价（DUE）标准，为临床合理用药提供参考。方法: 以注射用伏立康唑药品说明书为基础，参照相关规范、指南和文献，建立注射用伏立康唑DUE标准；并以此为依据，采用回顾性研究方法，对我院2017年7月至2018年7月121例使用注射用伏立康唑住院患者的用药指征、用药过程、用药结果、管理指标等进行综合评价分析。结果: 用药指征符合标准百分率为66.9%（目标值为90%）；给药途径、溶媒选择、配制方法符合标准百分率为100%（目标值为100%）；给药剂量和疗程符合标准百分率为31.4%和81.0%（目标值为95%）；微生物送检率为43.8%（目标值为80%）；用药有效率为50.4%（目标值为80%）；使用权限管理符合标准百分率73.6%（目标值100%）。结论: 本研究所建立的DUE标准可用于评价和规范注射用伏立康唑的临床合理使用。     

以球铁代铸钢气室支架的生产工艺

介绍了某气室支架的铸件结构及技术要求,根据技术要求在铸件结构上进行了改进,在应力较大的部分增加圆角过度,并将筋板掏空,使铸件质量减轻;在材料上,选用QT600-10代替ZG310-510,利用3 t中频炉单熔炼,原铁液成分为:w(C)3.7%~3.8%,w(Si)1.6%~1.9%,w(P)≤0.04%,w(S)≤0.02%,w(Mn)0.3%~0.4%,w(Cu)0.3%~0.4%,采用低Mg低RE的球化剂,加入量1%~1.1%,冲入法球化处理,一次孕育采用含Ba的SiFe孕育剂,加入量0.5%~0.6%,二次随流孕育采用Ba-Sr孕育剂,加入量为0.1%,出炉温度1 500~1 520℃,浇注温度1 400~1 440℃。最终生产的铸件金相组织和力学性能均符合技术要求,铸件气孔、砂眼、裂纹等铸造缺陷不超过0.5%,达到技术要求。     

CRG粘土旧砂再生系统的应用

通过选用一种旧砂再生处理设备对流水线的粘土砂进行再生,实现对旧砂的成分和性能的控制.生产表明:死粘土由20%降至12%,新砂加入量由20%下降至5%,型砂水分由6.3%下降至4.2%,废型率由20%下降至5%,铸件表面光洁度提高.     

Improvement of electrochemical action of zinc-rich paints by addition of nanoparticulate zinc

The influence of nanosized particles on electrochemical action of standard zinc-rich paints by means of SEM as well as potential and impedance measurements has been investigated. The motivation for doing this was to obtain additional electrical connection between the spherical microparticles themselves and zinc particles and steel substrate. Overall zinc content was at the level of 92% by weight. Samples with different concentration of nanoparticulate zinc (0%, 5%, 10% and 40%) were tested. Addition of 5–10% nanoparticulates extended the galvanic action of the coating in comparison to the standard zinc-rich coating.     

不同剂量辛伐他汀的降血脂作用

目的 比较不同剂量辛伐他汀降血脂效果。方法 43 例病人随机分为A、B 两组, A 组辛伐他汀开始剂量为5 mg/d, 治疗12 周效果不好者剂量增加到10 mg/d;B 组开始剂量为10 mg/d, 效果不好, 剂量增加20 mg/d 。疗程均为12 周。结果 与治疗前比, A 组5 mg/d 使TC、LDL 分别下降10.4%和15.4%;只有27.3%的病人TC 降低到正常值, 无1 例降到理想水平;9.1%的病人LDL 降低到正常, 4.5%病人降到理想值。剂量增加到10 mg/d, TC、LDL 分别下降24.6%和26.3%;50%病人TC 降到正常, 36.4%和22.7%病人TC 及LDL 降低到理想水平。B 组20 mg/d, 可使80.9%和66.7%的病人TC 及LDL 降到正常, 76.2%和80.9%的病人TC, LDL 降到理想水平。结论 辛伐他汀5 mg/d 不能很好降低血脂, 10 mg/d 可以使30%～50%病人血脂降到正常, 只有20 mg/d 才能使大多数病人血脂降低到理想水平。     

Mechanism of the Influence of Microadditions of Niobium on Microstructure and Properties of Thick-Sheet Low-Alloy Pipe Steel

Metal Science and Heat Treatment - The properties of thick-sheet steels of the 0.09% C – 1.5% Mn – 0.035% Si – (0.04 – 0.09)% Nb system (steel type 09G2B) with low (up to...     

Effect of sulfur dioxide on the oxidation of thin films of tin

The oxidation of thin films of tin in SO₂-air atmospheres containing 10%, 20%, 30%, 40%, 50%, and 60% SO₂ have been investigated at room temperature. Reaction kinetics were studied by the variation in resistance of thin films and growth patterns by metallography. Addition of SO₂ causes an increase in the oxidation rate of thin films of tin. Probable reactions at lower and higher percentages of SO₂ have been discussed.     

碳界面层制备工艺对SiC_f/SiC材料力学性能的影响

用低压化学气相沉积(LPCVD)法,以丙烯(C_3H_6)为碳源,氮气(N_2)为稀释气制备了2.5维连续碳化硅纤维增韧碳化硅(SiC_f/SiC)复合材料的碳界面层,其厚度为～0.1 mm.研究了不同丙烯含量(体积分数,下同)(60%,50%,45%)对碳层形貌、微观结构及SiC_f/SiC力学性能的影响.结果表明:当C_3H_6含量为60%时,热解碳层表面光滑,石磨化度高;当C_3H_6为50%和45%时,碳层粗糙,有很多较大颗粒存在,石磨化度低.3种复合材料的弯曲强度差别不大,分别为303,311和320 MPa.然而,当C_3H_6含量为60%时,材料韧性断裂,断裂功高;为50%和45%时,材料脆性断裂,断裂功低.不同的纤维拔出滑移阻力是SiC_f/SiC断裂行为不同的原因.     

Synthesis and characterization of nanoparticles of Alnico alloys

Nanoparticles of Alnico 4 (Fe–12% Al–28% Ni–5% Co) and Alnico 5 (Fe–8% Al–14% Ni–24% Co–3%–Cu) alloys with the mean particle diameter from 12 to 34 nm were successfully produced by hydrogen plasma metal reaction. The particle features, oxidization behavior and magnetic properties were studied. The nanoparticles have the same crystalline structure and lattice parameter as the master alloys, and a new phase or non-equilibrium phase has not been observed. With an increase in the mean particle, the oxidization temperature and the saturation magnetization are decreased, but the coercive force is enhanced.     

Fe含量对高纯Al-Si合金力学性能的影响

研究了Fe含量对高纯Al-Si合金力学性能的影响,并分析了Fe含量分别为<0.05%、0.1%、0.3%、0.5%时的金相组织和Fe含量<0.05%、0.5%、1.2%时的扫描断口。结果表明,对于高纯Al-Si合金,Fe含量小于0.5%时,随着Fe含量的增加,合金的抗拉强度和伸长率直线下降,当Fe含量增至0.5%～0.6%时,抗拉强度和伸长率基本降至最低值,而屈服强度略有升高。     

切割用燃烧型焊条高热剂的研究

混合使用CuO+Al和Fe_2O_3+Al作为高热剂,按CuO+Al系的质量分数分别为0%、25%、50%、60%、70%、80%、90%、100%配制切割用燃烧型焊条,并用之切割Q235钢板.根据切割长度、平均切口宽度、平均切口角分析各配方,确定CuO+Al系占高热剂60%～80%为宜.     

难冶金精矿烟尘中铁砷碳的脱除对氰化浸金的影响

以难冶金精矿烟尘为原料,研究了氢氧化钠浸出、硫酸浸出以及硫酸与氢氧化钠联合浸出对烟尘中砷、铁和碳脱除及氰化浸金的影响。结果表明:在氢氧化钠浓度为6mol/L时,砷、碳脱除率分别为99.66%和60.63%,金浸出率为58.90%,较直接氰化浸出仅提高4.60%,砷的有效去除不能有效提高金的浸出率。在硫酸质量分数为15%时,铁、砷和碳脱除率分别为33.65%、80.38%和12.59%,金的浸出率为80.40%,与氢氧化钠浸出相比,硫酸浸出解离铁能有效提高金的浸出率。烟尘分别经过质量分数为15%硫酸浸出后氰化浸金,两次2 mol/L氢氧化钠浸出和氰化浸金后,烟尘中铁、砷和碳的总脱除率分别为33.65%、95.63%和79.60%,渣率为80.33%。此时,金的总浸出率为91.90%,氰化渣中金的含量为3.31g/t。与烟尘直接氰化浸出相比金的浸出率提高37.60%。