化工进展
化工進展
화공진전
Chemical Industry and Engineering Progress
2015年
z1期
150-155
,共6页
表面%结垢%分形%界面%黏附
錶麵%結垢%分形%界麵%黏附
표면%결구%분형%계면%점부
surface%fractals%fouling%interface%adhesion
设备材料的表面粗糙程度对污垢颗粒界面黏附力的影响较大。本文以设备材料粗糙表面为研究对象，考察了传统指标和分形指标的尺度独立性，发现分形指标随尺度的变化分为不稳定分形区和稳定分形区。通过对二维表面轮廓线的分析，将区域分隔临界点的求取转化为取样长度和夹角α值的定量关系求解，通过实验得出其定量关系，找出稳定分形区。采用原子力显微镜测颗粒在不同粗糙表面的黏附力，结合固体污垢清除机理分析，发现表面的粗糙程度对界面黏附力的影响较大。研究表明Ra<0.4627μm 时，随着表面粗糙度增加，黏附力减小；1.3461μm<Ra<2.9755μm时，黏附力逐渐增大；Ra>3μm时，黏附力保持稳定。黏附力随着分形指标的变化而变化，其变化趋势与传统指标正好相反。随着分形维数的增大，黏附力先是保持稳定，后逐渐增大，随着加工工艺的改变，表面粗糙程度有个剧烈的变化，分维值锐减，后逐渐增大。
設備材料的錶麵粗糙程度對汙垢顆粒界麵黏附力的影響較大。本文以設備材料粗糙錶麵為研究對象，攷察瞭傳統指標和分形指標的呎度獨立性，髮現分形指標隨呎度的變化分為不穩定分形區和穩定分形區。通過對二維錶麵輪廓線的分析，將區域分隔臨界點的求取轉化為取樣長度和夾角α值的定量關繫求解，通過實驗得齣其定量關繫，找齣穩定分形區。採用原子力顯微鏡測顆粒在不同粗糙錶麵的黏附力，結閤固體汙垢清除機理分析，髮現錶麵的粗糙程度對界麵黏附力的影響較大。研究錶明Ra<0.4627μm 時，隨著錶麵粗糙度增加，黏附力減小；1.3461μm<Ra<2.9755μm時，黏附力逐漸增大；Ra>3μm時，黏附力保持穩定。黏附力隨著分形指標的變化而變化，其變化趨勢與傳統指標正好相反。隨著分形維數的增大，黏附力先是保持穩定，後逐漸增大，隨著加工工藝的改變，錶麵粗糙程度有箇劇烈的變化，分維值銳減，後逐漸增大。
설비재료적표면조조정도대오구과립계면점부력적영향교대。본문이설비재료조조표면위연구대상，고찰료전통지표화분형지표적척도독립성，발현분형지표수척도적변화분위불은정분형구화은정분형구。통과대이유표면륜곽선적분석，장구역분격림계점적구취전화위취양장도화협각α치적정량관계구해，통과실험득출기정량관계，조출은정분형구。채용원자력현미경측과립재불동조조표면적점부력，결합고체오구청제궤리분석，발현표면적조조정도대계면점부력적영향교대。연구표명Ra<0.4627μm 시，수착표면조조도증가，점부력감소；1.3461μm<Ra<2.9755μm시，점부력축점증대；Ra>3μm시，점부력보지은정。점부력수착분형지표적변화이변화，기변화추세여전통지표정호상반。수착분형유수적증대，점부력선시보지은정，후축점증대，수착가공공예적개변，표면조조정도유개극렬적변화，분유치예감，후축점증대。
Surface property of material has a great impact on the interfacial adhesion of particle and surface.Rough surfaces were used for studying scale feature of above two indicators.It could conclude from the above study of scale feature of fractal indicators that there existed two regions when fractal indicators change with scale,which were named unstable fractal region and stable region.In the process of analysing the two-dimensional surface contour,we transfered the finding of critical point into solving the quantitative relationship of sampling length and angleα.By the quantitative relationship,angleαcould be made 0 to obtain the critical sampling length.As long as the sample length is greater than the critical length,stable fractal region could be obtained, and then the stable fractal dimension could be calculated,which would not affected by the resolution of instrument.In this case the fractal dimension can reflect the inherent property of rough surface, which can be used as an accurate characterization of surface roughness.Through the analysis of cleaning mechanism of solid dirt,we find that surface roughness has a great impact on interfacial adhesion.The results show that adhesion force changes with surface roughness,Ra<0.4627μm,adhesion force decreases with the increase of surface roughness;1.3461μm<Ra<2.9755μm,adhesion force increases gradually;Ra>3μm,adhesion force remains the same.Adhesion force also changes with fractal indicator,it changes the opposite trend with surface roughness.
