简介:通过化学沉积法制备Ni-P、Ni-Mo-P单镀层以及与其成分相同的Ni-P/Ni-Mo-P双镀层。采用纳米压痕法和AFM分析测量镀层表面和截面的残余应力,并用电化学法评估镀层在10%HCl溶液中的腐蚀行为,以获得镀层残余应力与腐蚀行为之间的关系。结果表明:Ni-P单镀层和Ni-P/Ni-Mo-P双镀层表现为残余压应力,分别为241和206MPa;Ni-Mo-P单镀层呈现出257MPa的残余拉应力。残余压应力阻止镀层中孔洞的生长,保护镀层的完整性。Ni-P/Ni-Mo-P双镀层比它们的单镀层具有更好的耐蚀性。此外,镀层的应力状态影响其腐蚀形式。
简介:InordertocontrolthesizeanddistributionofthehighconductiveFe2PinLiFePO4/Fe2Pcomposite,twodifferentcoolingrates(Fast:15℃·min-1,Slow:2℃·min-1)wereemployedaftermechanicalalloying.Thedischargecapacityofthefastcooledwas83mAh·g-1andtheslowcooled121mAh·g-1.TheparticlesizeofthesynthesizedpowderwasexaminedbytransmissionelectronmicroscopyanddistributionofFe2Pwascharacterizedusingscanningelectronmicroscopy(SEM).Inaddition,two-stepheattreatmentwascarriedoutforbetterdistributionofFe2P.X-raydiffraction(XRD)andRietveldrefinementrevealthatLiFePO4/Fe2Pcompositeconsistsof95.77%LiFePO4and4.33%ofFe2P.
简介:Weldshapecontrolisafundamentalissueinautomaticwelding.Inthispaper,adoublesidevisualsystemisestablishedforpulsedgasmetalarcwelding(P-GMAW),andbothtopsideandbacksideweldpoolimagescanbecapturedandstoredcontinuouslyinrealtime.Byanalyzingtheweldshaperegulationwiththemoltenmetalvolume,sometopsideweldpoolcharacterizedparameters(WPCPs)areproposedfordeterminingpenetrationinbuttweldingofthinmildsteel.Moreover,someBPnetworkmodelsareestablishedtopredictbacksideweldpoolwidthwithweldingparametersandWPCPsasinputs.
简介:焊接技术的发展都是以焊接高效率化和高产能化为最大目标。要实现高效率化焊接重要措施之一就是提高焊接速度,一般熔化极气保焊的焊接速度仅为0.3-0.5m/min。当焊接速度较高时(〉0.6m/min)易产生焊道不连续、咬边和产生大量气孔等缺陷,因而研究、推广焊接高效率化的技术成果是我国焊接领域里的重要课题。本文介绍一种在造船行业和钢结构焊接领域里常见型钢简捷、高效化平角焊接方法。即用双丝-熔池简捷高效快速焊接(焊接速度为1.2-1.5m/min,焊脚高度5mm)时也能达到良好的焊接规范和焊接性能的高效化平角焊接方法。经过多年的在造船行业和钢结构焊接中的T型钢焊接生产中证明,采用双丝-熔池气体保护焊可提高T型钢生产效率和焊接质量,减少焊接变形,因而双丝-熔池气体保护焊得到快速发展和广泛的应用。
简介:Thehotdeformationbehaviourof7075aluminiumalloyreinforcedwith10%ofSiCparticleswasstudiedbyemployingboth'processingmaps'andmicrostructuralobservations.Thecompositewascharacterizedbyemployingopticalmicroscopetoevaluatethemicrostructuraltransformationsandinstabilityphenomena.Thematerialinvestigatedwasdeformedbycompressioninthetemperatureandstrainraterangesof300-500℃and0.001-1.0s-1,respectively.Thedeformationefficiencywascalculatedbystrainratesensitivity(m)valuesobtainedbyhotcompressiontests.Thepowerdissipationefficiencyandinstabilityparameterswereevaluatedandprocessingmapswereconstructedforstrainof0.5.Theoptimumdomainsandinstabilityzonewereobtainedforthecomposites.Theoptimumprocessingconditionsareobtainedinthestrainraterangeof0.1-0.9s-1andtemperaturerangeof390-440℃withtheefficiencyof30%.
简介:55%SiCp/A356(体积部分)以铜锌金焊接在把Zn-Al合金用作filler金属的空中的composites被调查。在以铜锌金焊接的过程期间,超声的颤动为结合被用于样品,进在基础材料的矩阵合金的filler金属的重要溶解发生了。当以铜锌金焊接的温度被增加,在基础材料的部分融化层的厚度增加了。原文如此,在基础材料的部分融化层的粒子在超声的行动下面被变成液体filler,有同类地分布式的加强的一张契约在团结以后被获得。体积部分原文如此,在契约的粒子能被改变以铜锌金焊接的温度改变。最大值原文如此,契约材料的粒子体积部分在500的以铜锌金焊接的温度到达了37%?????????????敷摬摥??
简介:AmorphousNi–PcoatingwasplatedonAZ31magnesiumalloyviatheelectrolessplatingtechnique,andtheplatedalloywassubsequentlyannealed.X-raydiffraction(XRD),scanningelectronmicroscopy(SEM),energydispersivespectroscopy(EDS),anddifferentialscanningcalorimetry(DSC)wereusedtocharacterizethecoating.Theresultsshowthatthehardnessofthecoatingismuchhigherthanthatofbaremagnesiumalloy,whichfurtherincreasesaftercrystallization.Theelectrochemicalpolarizationandsaltspraytestsshowthatthecoatingexhibitsamuchhighercorrosionresistancethanthatofthebaremagnesiumalloy.Moreover,thecrystallizedcoatingstillexhibitsamuchstrongercorrosionresistancethanthatofthebaremagnesiumalloy,althoughitscorrosionresistanceislowerthanthatoftheas-platedone.
简介:研究析出强化AW-6016-T4金属板材的低温成形行为。利用拉伸和Nakazima测试方法获得材料在-196至25°C范围内的流变曲线和成形极限曲线。结果表明,材料的强度和伸长率随温度的降低而增大。背散射电子衍射(EBSD)研究表明变形材料在室温和低温下显微组织有细微区别。但连续加热差热分析表明析出动力学之间无明显区别。本研究结果表明低温变形可用于制造8mm深的B柱,而常温变形只能制造6mm深的B柱。