简介:Thecombinedquadraticorthogonalregressionmethodofexperimentdesignwasemployedtoexploretheeffectsofprocessparametersofplasmanitridingoftantalumsuchastotalpressure,temperatureandoriginalhydrogenmolarfractiononthehardness,roughnessandstructureofnitridingsurfaces.Theregressionequationsofhardness,roughnessandstructureweregivenaccordingtotheresultsofregressionandstatisticanalysis.Andthediffusionactivationenergyofnitrogenintantalumonplasmanitridingconditionswascalculatedaccordingtotheexperimentaldataofhardnessofplasma-nitridingoftantalumvstimeandtemperature.Thediffusionactivationenergycalculatedbelongsto(155.49+10.51)kJ/mol(783-983K).
简介:Titaniumandtitaniumalloyshaveseveraladvantages,butthecostoftitaniumalloysisveryexpensivecomparedwiththetraditionalmetalmaterials.Thisarticleintroducestwonewlow-costtitaniumalloysTi-2.1Cr-1.3Fe(TCFalloy)andTi-3Al-2.1Cr-1.3Fe(TACFalloy).Inthisstudy,weusedCr-Femasteralloyasoneoftherawmaterialstodevelopthetwonewalloys.Weintroducethemicrostructureandtensilepropertiesofthetwonewalloysfromβsolutiontreatedwithdifferentcoolingmethods.Optica...
简介:Thechloridizingsegregationandmagneticseparationoflow-gradenickellateritesfromYunnanprovinceofChinawasinvestigated.Thenickellateriteswerecharacterizedbymicroscopicinvestigations,usingX-raydiffractometry(XRD)andenergydispersivespectrometry(EDS)techniques.Thepellets,whichwerepreparedwithmagnesiumchlorideandcokeaschlorideagentandreductantrespectively,wereheatedtoahightemperature,andthepelletsaftercoolingwerecrushedformagneticseparation.Aseriesofexperimentswereconductedtoexaminetheeffectofchlorinatingagentdosage,reductantdosage,chloridizingtemperatureandchloridizingtimeonenrichmentgradeofNiandCo.TheresultsindicatethatthefourfactorshavesignificanteffectsontheextractionsofNiandCo.Theoptimumconditionsareasfollows:theamountsofmagnesiumchlorideandcokeare6%and2%,respectively,chloridizingtemperatureis1253K,andchloridizingtimeis90min.Undertheconditions,extractionsofNiandCoreach91.5%and82.3%,respectively.
简介:Aprocessoftheselectiveleachingofnickelfromlow-sulfurNi-Cumatteatatmosphericpressurewasdescribed.ThismattewasobtainedfromhighgradeNi-Cumattebymagneticseparation,whichmainlycontainedNi-Cualloyandasmallquantityofsulfides.Firstly,theacid-oxygen(CuSO4-H2SO4-O2)leachingofthemattewasconductedatatmosphericpressure.WhenthesolutionpHvaluereached1.0-2.0,theoxygenflowwasceased.Then,theaqueouscopperwasrejectedbycementationreactionwithNiinthealloy.ThemineralogicalcharacteristicsofthematteintheprocesswereanalyzedbyX-raydiffractometry,opticalmicroscopyandscanningelectronmicroscopy.Andtheeffectsofvariationsintemperature,particlesizedistribution,oxygenflowrate,pulpdensity,initialacidconcentrationandinitialconcentrationofcopperionwereinvestigated.
简介:Theeffectsoflow-CoAB5typehydrogenstoragealloyspreparedbyquenchingandannealingontheperformancesofMH-Nibatterieswereinvestigated,andthecharacteristicsofthelow-CoAB5typehydrogenstoragealloyswerecomparedwiththoseofthehigh-CoAB5typehydrogenstoragealloyaswell.Theresultsshowedthatthefasterthecoolingofthelow-Cohydrogenstoragealloyis,thebetterhomogeneityofthechemicalcompositionforthealloyandthelongercyclelifeofthebatteryare,buttheelectrochemicaldischargecapacityandhigh-ratedischargeabilityarereduced.Thehigh-ratedischargeabilityandchargeretentionofMH-Nibatteriesfortheconventionalas-castannealedlow-Cohydrogenstoragealloyweresuperiortothosefortherapidlyquenchedlow-Cohydrogenstoragealloyandthehigh-Cohydrogenstoragealloy,butalittleinferiorinthecyclelife.
简介:Reducingthemanufacturingcostofsolarcellsisnecessarytotheirindustrialproduction.Electrodepositingisaneffective,non-vacuummethodwhichisverysuitableforcuttingthemanufacturingcostofthinfilmsaswellasdevelopingitslarge-scaleindustrialproduction.Inthisstudy,about1-μm-thickCu(In,Ga)Se_2(CIGS)precursorswereelectrodepositedonMo/glasssubstratesinaqueoussolutionutilizingathree-electrodepotentiostaticsystem.Triethanolaminewasusedascomplexingagent,andallparametersofelectrodepositionwerepreciselycontrolled.Afterthat,theelectrodepositedprecursorswereselenizedinaSeatmospherewithdifferentheatingramprates(60and600℃·min~(-1)).High-qualityCIGSfilmswereobtained,andtheircharacteristicswereinvestigatedbyX-rayfluorescence,scanningelectronmicroscopy,energydispersivespectroscopy,X-raydiffraction,Ramanspectraandnear-infrared-visible(NIR-Vis)spectra.Theresultsrevealthattherearemanydifferencesbetweenthepropertiesofthefilmsunderdifferentheatingrates.Finally,CIGSsolarcellswerefabricatedusingafastandaslowheatingrate.Themaximumefficienciesachievedforthefilmsselenizedat60and600℃-min~(-1)are3.15%and0.71%,respectively.
简介:Au/-Al2O3催化剂被免职降水方法为低集中白酒溪流(甲醇,乙醇,iso-propanol和n-propanol)的催化燃烧作好准备。催化剂被X光检查光电子描绘光谱学(XPS),X光检查diffractometry(XRD)和精力散X光检查微分析(版本)技术。XPS结果证明仅仅催化剂的表面上有Au0。XRD模式证明Au高度大概在-Al2O3上被驱散。为有2.0g/m3的集中的甲醇,乙醇,iso-propanol和n-propanol的完全的变换的温度是60,155,170和137?,分别地但是他们完全在60,220,260和217点被使矿物化进CO2和H2O吗?分别地在优化催化剂上。催化剂的活动在130h是稳定的。为催化甲醇消除的动力学跟随了伪--首先订表示为r=0.6528c0+0.084的反应2。明显的激活精力的价值是在反应温度的范围的54.7kJ/mol。
简介:用销-盘摩擦磨损试验机考察Z71E压铸镁合金在载荷为10~50N时的高温摩擦学行为,利用光学显微镜(OM)和扫描电镜(SEM)对磨损表面和亚表面进行分析,通过光学显微镜(OM)、X射线衍射仪(XRD)、差示热扫描(DSC)等对AZ71E合金的高温微观结构、热稳定性和力学性能进行研究。结果表明:随着载荷和滑动距离的增加磨损率增大,而摩擦系数则随着载荷的增加而减少。在低载荷时,AZ71E镁合金的磨损机制主要是磨粒磨损;在150℃和高载荷下,粘着磨损和轻微的剥层磨损是主要的磨损机制;而在200℃及高载荷下,镁合金的主要磨损机制是严重的剥层磨损和熔融磨损。AZ71E镁合金的高温摩擦学性能提高的内在机制是AZ71E镁合金中第二相Al11Ce3使镁合金的高温拉伸和延展性能显著提高。
简介:Aluminum,themainimpurityinthelixiviumofweatheredcrustelutiondepositedrareearthore,notonlyresultsinanincreasingconsumptionofprecipitantintherareearthprecipitationprocess,butalsolowersthepurityoffinalrareearthproduct.Aluminumintheweatheredcrustelution-depositedrareearthorelixiviumshouldberemoved.Neutralizinghydrolysismethodwasemployedtoremovealuminumfromthelixivium.HexamethylenetetraminewasfoundtobetheoptimumpHregulatorfortheremovalofaluminuminthelowconcentration.WhenusedtoadjustthepHvalueofthelixiviumto5.0,aluminuminthelixiviumcanbeeffectivelyremovedintheformofaluminumhydroxideprecipitationwithremovalrateof97.60%.Itshowsthathexamethylenetetraminehasagoodeffectontheremovingofaluminumionsfromthelowconcentrationlixivium.Moreover,hexamethylenetetramineinremovingaluminumfromlixiviumhaslittleadverseeffectontheREprecipitationprocess.
简介:SincethelowandmediumgradeoxideoresintheMainandEasternMiningAreasattheBayanOboMinehaveahighgradeofNb2O5andlargeorereservesandarerichinmanyelements,theyareofgreatervaluetouseindevelopmentandrecoverythanotherkindsofniobiummineralsresources.Thedisseminationcharacteristicsandprocessingpropertiesoffourtypesofniobiummineralsaresummarisedandmethodsandresultsofniobiummineralprocessingarealsodescribed.