本文選題：Ni-Cr-Fe多孔材料 + 梯度多孔材料�。� 參考：《湘潭大學(xué)》2017年碩士論文

【摘要】：金屬多孔材料具有密度小、強度高、可焊接等特點,對節(jié)約能源及保護(hù)環(huán)境具有極其重要的意義,但在實際應(yīng)用中其抗腐蝕性較差,限制了諸多工業(yè)領(lǐng)域的應(yīng)用。并且隨著世界工業(yè)的快速發(fā)展,對工業(yè)產(chǎn)品及環(huán)境保護(hù)的要求越來越高,梯度多孔材料能同時兼顧良好的過濾精度與優(yōu)秀的過濾通量,特別是在工業(yè)領(lǐng)域中過濾與分離的應(yīng)用。梯度多孔材料對提升工業(yè)生產(chǎn)效率及保護(hù)環(huán)境有良好的作用。因此,對金屬多孔材料抗腐蝕性能及梯度化研究勢在必行。本文采用粉末冶金方法,制備了Ni-Cr-Fe多孔材料。運用電化學(xué)及浸泡腐蝕的方法探究了Ni-Cr-Fe多孔材料在2mol/L的KOH溶液中的腐蝕行為及腐蝕機理。采用SEM、XPS及孔道測試儀表征前后孔結(jié)構(gòu)參數(shù)、材料表面形貌及物相。結(jié)果顯示:Ni-Cr-Fe多孔材料孔隙豐富、聯(lián)通,在2mol/L的KOH溶液的抗腐蝕性能優(yōu)異,開路電位在84小時后達(dá)到穩(wěn)定狀態(tài)。Ni-Cr-Fe多孔材料在2mol/L的KOH溶液中浸泡腐蝕600h后,表面較光滑,最大孔徑及透氣度穩(wěn)定。XPS測試表明,Ni-Cr-Fe多孔材料的腐蝕層主要由內(nèi)層的Cr與Fe的氧化物(Cr2O3/FeCr2O4)和外層Ni的氧化物(NiO/NiOOH/Ni(OH)2)構(gòu)成。FeCr2O4氧化膜比NiO更致密,能保護(hù)內(nèi)層金屬不被繼續(xù)腐蝕。通過400℃高溫純氯氣腐蝕720h,Ni-Cr-Fe多孔材料孔結(jié)構(gòu)變化較小,表面孔隙較豐富,具體透氣度下降約13.4%,最大孔徑下降約4.3%,表現(xiàn)出優(yōu)異的腐蝕抗力。通過XRD及XPS分析表明:腐蝕后的Ni-Cr-Fe多孔材料金屬表層生成了較多的NiCl3,內(nèi)層生成了Cr2O3、CrCl3和FeCl2等氯化物,這些物質(zhì)具有較高熔點和低蒸氣壓,并且Cr2O3較致密,能阻止氯氣繼續(xù)擴(kuò)散腐蝕內(nèi)層金屬。為了進(jìn)一步優(yōu)化多孔材料的過濾精度,采用粉末冶金刷涂法,制備了同質(zhì)Ni-Cr-Fe梯度多孔材料。通過測試梯度多孔材料孔結(jié)構(gòu)、膜層厚度以及結(jié)合強度表征其性能。結(jié)果表明:粉末粒度及膜層厚度對梯度Ni-Cr-Fe多孔材料的孔結(jié)構(gòu)性能影響較大,當(dāng)粉末粒度差異較大時,細(xì)粉膜層易塌陷并堵塞大孔,整體透氣度大大減小;另外,當(dāng)膜層較薄時,易造成膜層結(jié)構(gòu)不完整,當(dāng)膜層較厚時,又嚴(yán)重影響梯度多孔材料的過濾通量。因此需要增加一定厚度的過渡層才能達(dá)到良好過濾精度與優(yōu)秀的過濾滲透通量兼顧的效果。當(dāng)過渡層的厚度為80μm,表面膜層厚度為30μm時,最大孔徑為6μm,透氣度為936m3·m-2·h-1·KPa-1,透氣度下降22.64%。此外,由于支撐體與膜層同質(zhì),一階和二階梯度Ni-Cr-Fe多孔材料都具有較好的結(jié)合強度及抗熱震性能,能滿足在較苛刻環(huán)境中的應(yīng)用。
[Abstract]:Metal porous materials have the characteristics of low density, high strength and weldability, which are of great significance for saving energy and protecting environment. However, the corrosion resistance of metal porous materials is poor in practical application, which limits the application of many industrial fields. With the rapid development of industry in the world, the requirements for industrial products and environmental protection are becoming higher and higher. Gradient porous materials can take into account both good filtration accuracy and excellent filtration flux, especially in the application of filtration and separation in the industrial field. Gradient porous materials play a good role in improving industrial production efficiency and protecting environment. Therefore, it is imperative to study the corrosion resistance and gradient of metal porous materials. In this paper, Ni-Cr-Fe porous materials were prepared by powder metallurgy. The corrosion behavior and corrosion mechanism of Ni-Cr-Fe porous materials in KOH solution of 2mol/L were investigated by electrochemical and immersion corrosion methods. The structure parameters, surface morphology and phase of the material were characterized by means of SEM XPS and pore channel tester. The results showed that the porous material was rich in pores and interlinked. The corrosion resistance of KOH solution in 2mol/L was excellent. The open circuit potential reached stable state after 84 hours. The surface of Ni-Cr-Fe porous material was smooth after being immersed in KOH solution of 2mol/L for 600h. XPS measurements show that the corrosion layer of Ni-Cr-Fe porous material is mainly composed of Cr _ 2O _ 3 / Fe oxide (Cr _ 2O _ 3 / Fe _ 2O _ 4) and the outer Ni oxide (Nio / NiOH / nio _ (H _ 2O _ 2), which is more compact than NiO and can protect the inner layer metal from further corrosion. The pore structure of Ni-Cr-Fe porous material corroded at 400 鈩，

本文編號：1815575