資源描述:
《鎂基非晶合金及復(fù)合材料的制備與力學(xué)性能的研究》由會(huì)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(kù)。
1、沈阿I:r業(yè)大學(xué)碩十學(xué)位論文摘要利用NaCl顆粒作為預(yù)制型,采用滲流鑄造方法制備了AZ91泡沫合金,樣品孔隙之闋具有受努魄連逶性;泡沫密度鴦O。724g/em3,琵驤搴海0,602。纛縫實(shí)驗(yàn)結(jié)暴襲璞AZgl鑲合金泡沫材料的塑性交形能力明顯高于鑄態(tài)AZ91鎂合金。在猶隙被壓合的過(guò)程中,泡沫材料在低威力條件下發(fā)生剪切破壞。這一變形機(jī)制在金屬泡沫材料中尚洙見到報(bào)遴。同時(shí)采翔滲流鑄造法分別制備了不閼體積分?jǐn)?shù)Fe絲和鋼網(wǎng)增強(qiáng)的AZ91鏇合金復(fù)合材料.用真空淬火爐迅速加熱AZ91鎂含金到700℃發(fā)右.保溫60分鐘,待A
2、Z91合金寵全熔佳愛(ài),凌2x105Pa戇Ar氣佟震下椽AZ91鎂會(huì)會(huì)溶滾滲滾聚&絲孛,勢(shì)逐速浮入水中,經(jīng)過(guò)快速淬火,形成所要求的試樣。該工藝鼴求嚴(yán)格控制加熱溫度和保溫時(shí)『白J才能取得良好的效果。通過(guò)光學(xué)顯微鏡和掃描電鏡觀察了復(fù)合材料的結(jié)構(gòu)和壓縮時(shí)的斷瓣形貌,蒡穰莛與鎂合金秘磚篦。結(jié)暴發(fā)凌:復(fù)合棗孝辯戇顴裂強(qiáng)度較AZgl鎂會(huì)會(huì)藪裂強(qiáng)度明顯提高,提高的幅魔隨著Fe絲和鋼網(wǎng)體積分?jǐn)?shù)的增加而增加。材料的破壞方式也受Fe絲和鋼網(wǎng)數(shù)量的影響。采焉奏空鑣模澆鑄法鍘器了霆耱Mg,Cu-Nd系霧蒺臺(tái)會(huì).均霹叛形殘壹經(jīng)必2mm
3、熬犬塊非晶合裊。其中M955Cu35Ndll火塊非晶合金輿有明顯且較高的玻璃轉(zhuǎn)變溫度Tg(419K),高的晶化初始溫度最(472K),寬的過(guò)冷液相區(qū)ATe=瓦一rg(53K),是非晶形成戇力露熬穩(wěn)定經(jīng)較毫款會(huì)金。瓢娶3Cu37Ndlo室{鑫壓繚藜裂強(qiáng)度鰳糍達(dá)685MPa。采用銅模鑄造法制備了直徑2mm,3mm的Mg—Ni。Zn,Y系復(fù)合材料。經(jīng)實(shí)驗(yàn)測(cè)試,由于快速凝固三種成分合金均具有部分非齲特征.?dāng)嗔逊绞綖榇嘈詳嗔眩哂泻茼氲臄嗔鸯投龋?00MPa班土.繕織照片顯示部分菲鑫特{菱。關(guān)鍵詞:滲流鑄造,破壞機(jī)
4、制,泡沫.非晶形成能力,鎂基非晶合金及復(fù)合材料的制各與力學(xué)性能的研究FabricationAndStudyOfMechanicalPerformanceOfMagnesium-baseAmorphousAndMagnesiumMatrixCompositesMaterialAbstractTheAZ91magnesiumalloyfoamwithadiameterof9mmwerefabricatedbyusingvacuuinmeltinfiltrationandwaterquenchingmethods
5、.NaClsaltwasusedasaplaceholderinthisinvestigation.Theporosityanddensitywere0.602and0.724g/cm3respectivelyfortheAZ91magnesiumfoam.Theporeswereevenlydistributedinthematerial.TheplasticstrainduringcompressionfortheAZ91magnesiumalloyfoamismuchhigherthanthatoft
6、heas—eastAZ91magnesiumalloyfabricatedbythesameprocess.Thefractureeventoccurredatlowstressduringtheporesvanishing.whichisthefirstevidenceobservedinmetalfoammaterialsduringcompressionaccordingtOOurknowledge.TheAZ91magnesiumbasedcompositesreinforcedbywireands
7、teelwebhavebeenfabricatedbymeltinfiltratingcastingmethod.Thevolumefractionofwireandsteelwebaledifferent.Anopticalmicroscopyandascanningelectronicmicroscopywereusedtoinvestigatethestructureofthecompositeandthemicroscopicmorphologiesofthefracturesurface.Thec
8、ompressionresultsshowthattheyieldingstrengthofthecompositesishigherthanthatoftheAZ91magnesiumalloy,andtheextentisincreasedwithincreaseofthevolumefractionofwireandsteelweb.Inthesaluetime,thevolumefractionofwir