資源描述:
《高比重鎢合金再生技術(shù)及再生合金性能研究》由會員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫。
1、碩十學(xué)付論文摘要隨著地球原生資源的日益短缺,人們迫切需要對大量工業(yè)和生活的廢棄物進(jìn)行二次開發(fā)。鎢資源作為一種重要的戰(zhàn)略資源,各國都非常重視對其廢料進(jìn)行回收再利用。本文探索并獲得了一種簡便、高效的鎢廢屑回收技術(shù),制備的再生鎢基高合金力學(xué)性能優(yōu)良。本文采用氧化一兩階段還原工藝,將某工業(yè)牌號的w_Ni—Fe—Co合金機(jī)加工廢屑分別進(jìn)行酸堿清洗預(yù)處理,在900℃氧化4h,然后經(jīng)球磨獲得氧化物粉末,再在600℃/90min一750℃/90min氫氣中兩段還原,獲得氧含量0.17%、中位徑粒度3.53pm的再生粉末。該再生粉末具有優(yōu)良的燒結(jié)特性。用再生粉末直接
2、經(jīng)1200℃/2h+1450℃/45min兩段燒結(jié),1050℃/3h真空熱處理后,制備出晶粒尺寸僅為3~5um、粘結(jié)相分布均勻的再生合金。再生粉末預(yù)合金化導(dǎo)致了活化燒結(jié),降低了燒結(jié)溫度,縮短了燒結(jié)時間,減少了晶粒的長大傾向。用回收粉末及鎳、鐵元素粉配制成9lW-6Ni一3Fe系合金的混合粉,經(jīng)壓制、脫膠、燒結(jié)得到再生高比重鎢合金,再生合金性能同非回收粉末所制備的合金性能相當(dāng)。研究還表明:再生鎢合金的密度隨燒結(jié)溫度的升高先升高而后有所降低,最大值為17.12g/cd,硬度隨燒結(jié)溫度的升高而降低。當(dāng)燒結(jié)溫度為1440℃時再生合金的強(qiáng)度和塑性達(dá)到較好的配
3、合,拉伸強(qiáng)度為922.95MPa,延伸率為20.18%。經(jīng)真空熱處理后,再生鎢合金性能得到改善,抗拉強(qiáng)度和延伸率得到不同程度的提高,其中,抗拉強(qiáng)度比熱處理前提高了約6.44%,延伸率比熱處理前提高了約43.42%。關(guān)鍵詞鎢基高比重合金,廢屑回收,氧化一還原工藝,活化燒結(jié),熱處理碩{‘中伸論文摘耍ABSTRACTWitlltheshortnessofrawresources.1argequantityofscrapinindustryanddailyliveneedtOberecycledurgently.Asanimportantstrategic
4、allyresource,thescraprecycleofthetungstenarepaidmuchattentiontoinmanycountries.Inpresentpaper,anewrecyclingtechnique,theoxidization+two-stagereductionprocess,oftungstenhighdensityalloyscrapwasinvestigatedandprovedtObeaneffectiveandsimplemethod.Thealloyswiththeregeneratepowdera
5、srawmaterialsshowexcellentmechanicalproperties.ThescrapsofW-Ni.Fe.Coalloywerewashedbyalkalinesolutionandsubsequentlyoxidizedfor4hoursat9000C,followedbymilling.111emilledoxidepowderWasreducedfor90minat600℃firstlyandthenat750℃attheatmosphereofhydrogen.neregeneratepowderWasobtain
6、edwimoxygencontentofO.17%andtheD(v,O.51of3.531amandhasexcellentsinteringproperties.Theregeneratealloyswitllthefulldensity,distributed-homogeneouslybondingphaseandgrainsizesof3—5pmwerepreparedbytwo-stagesintering(1200*C,2h+1450。C,45min)andsubsequentheattreatmentinvacuum(1050"C,
7、3h).Theresultsalsorevealthatthepre—alloyingofregeneratepowderresultsinactivatedsintering,whichdecreasesthetemperatureofliquidsintering.Becausethesolidsintering,thefirststageofsintering,almostdensitiesthealloys,thesinteringatthesecondstagemakestheliquidsinteringtimeshorter,limi
8、tingthegrowthofgrains.Thepowderof91W-6Ni一3FeTungstenheavymeta