|
|
|
Abstract Two Ni-Ag alloys, containing Ni of 50 at% and 75 at %, denoted as Ni-50Ag and Ni-25Ag were consolidated with hot pressing (HP) proce ssing after mechanical alloying (MA) for 80 hr. The nanocrystalline alloys have been oxidized in air at 600-700 ℃ for 24 hr.Ni-50Ag alloy undergoes an inte rna l oxidation of nickel associated with the formation of a continuous outermost la yer of silver metal and has oxidation rates larger than those of pure nickel. On the contrary, Ni-25Ag alloy forms a continuous NiO layer surmounted by a discon tinuous silver layer, while the internal oxidation is suppressed. These results are interpreted on the basis of the two-phase nature of the alloys and of their particularly small grain size.
|
|
Received: 05 July 2000
|
|
|
[1]HadjipanayisGC ,SiegelRW ,etal.NanophaseMaterials:Synthesis,Properties,Applications[M ].London:KluwerAcademicPublishers,1994
[2]MassalskiTB ,OkamotoH ,SubramanianPR ,etalEds.BinaryAlloyPhaseDiagrams[M ].2nded.,ASMInternational,Ma terialsPark,OH ,1990,64.
[3]ZhaoZL ,ZhaoY ,NiuY ,etal.Synthesisandcharacteristicsofconsolidatednanocrystallinetwo-phaseAg50Ni50 alloybyhotpressing[J].J .All.Comp.,2000,307:254
[4]KofstadF .HighTemperatureCorrosion[M ].London:ElsevierAppliedScience,1988
[5]AtkinsonA ,RaylorRL ,HughesAE .HighTemperatureCorrosion[M ].Houston:NACE ,1983,110
[6]WagnerC .Theoreticalanalysisofthediffusionprocessdeterminingtheoxidationrateofalloys[J].J .Electrochem.Soc.,1952,99:369
[7]RappRA .Microstructuresandmechanismofinternaloxidationitseffectandpreventioninhightemperaturealloyoxidation[J].Corrosion,1965,21:382
[8]GesmundoF ,NiuY ,VianiF .Possiblescalingmodesinhigh-temperatureoxidationoftwo-phasebinaryalloys,PartII:lowoxidantpressures[J].Oxid.Metall.,1995,43:379
[9]CrankJ.TheMathematicsofDiffusion[M].Oxford:ClarendonPress,UK ,1976.
[10]WangG ,GleesonB ,DouglassDL .Adiffusionalanalysisoftheoxidationofbinarymultiphasealloys[J].Oxid.Met.,1990,35:333
[11]HartEW .Ontheroleofdislocationinbulkdiffusion[J].ActaMetall.,1957,5(5):597
[12]WangF .TheeffectofnanocrystallizationontheselectiveoxidationandadhesionofAl2O3scales[J].Oxid.Met,1997,48:215
[13]GesmundoF ,VianiF ,NiuY .Theinternaloxidationoftwo-phasebinaryalloysunderlowoxidantpressures[J].OxidMet.,1996,45:51
[14]NiuY ,GesmundoF ,VianiF .Theairoxidationoftwo-phaseCu-Crat700-900℃[J].OxidMet.,1997,48:357
[15]ChiangKT ,MeierGH ,PettitFS .MicroscopyofOxidationIII[C],NewcombeSB ,LittleJA ,Ed.London:TheInstituteofMaterials,1997,453
[16]GuruswamyS ,ParkSM ,HirthJP ,etal.InternaloxidationofAg-Inalloys:stressreliefandtheinfluenceofimposedstrain[J].OxidMet.,1986,26:77 |
| No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
