【摘要】：隨著數(shù)字通信系統(tǒng)的發(fā)展和各種電子設(shè)備的廣泛應(yīng)用,電磁輻射污染已經(jīng)成為一種新的社會(huì)公害。針對(duì)目前日益惡化的電磁環(huán)境以及軍事隱身及防護(hù)的需求,研究寬頻、高效、滿足結(jié)構(gòu)承載要求的水泥基復(fù)合吸波材料具有十分重要的意義。論文針對(duì)目前水泥基復(fù)合吸波材料存在吸收效能低、質(zhì)量大、成本高、穩(wěn)定性差、承載力低等問(wèn)題,從阻抗匹配,吸波效能和結(jié)構(gòu)承載等方面進(jìn)行綜合設(shè)計(jì),首先探討了納米CoFe2O4吸波劑的制備方法,然后分別探討了摻合料、多孔集料、吸波劑、纖維等組分的品種以及摻量對(duì)高性能水泥復(fù)合吸波材料的強(qiáng)度、電阻率以及吸波性能的影響。試驗(yàn)結(jié)果表明,將原料硝酸鈷、硝酸鐵和氫氧化鈉和分散劑聚乙烯醇按1:2:8.1:0.25的化學(xué)計(jì)量比,球磨1h后移入電阻爐中在700℃煅燒3 h,即可制備出粒徑約為50 nm純的CoFe2O4粉末。在16~20 GHz電磁波頻率范圍內(nèi)測(cè)試了不同厚度樣品的吸波性能,當(dāng)樣品的厚度為3 mm時(shí),其反射率值最小為-8.6dB,表明樣品具有較好的吸波性。此外將納米鐵氧體粉末在濃度為1.0%的六偏磷酸鈉溶液中進(jìn)行超聲分散30min,有助于改善納米鐵氧體的團(tuán)聚現(xiàn)象。高性能水泥復(fù)合吸波材料影響因素的研究結(jié)果表明,當(dāng)摻加20%粉煤灰和15%礦粉時(shí),水泥砂漿的強(qiáng)度最高,電阻率較小,吸波性最好;采用玻化微珠制備的水泥砂漿,其抗壓強(qiáng)度比采用膨脹珍珠巖的砂漿強(qiáng)度高,電阻率小;當(dāng)復(fù)摻3%石墨和3%納米鐵氧體時(shí),混凝土在低頻和高頻段均具有較好的吸波性。粘土陶粒輕骨料混凝土和浮石輕骨料混凝土的抗壓強(qiáng)度相近,但后者的電阻率比前者的電阻率小,且吸波性好;在混凝土中摻加1%的鋼纖維不僅能提高其抗壓強(qiáng)度,降低電阻率,且大大改善其吸波性能。綜合上述試驗(yàn)結(jié)果,確定出制備C20高性能水泥基復(fù)合吸波材料的配合比為:水泥:粉煤灰:礦粉:納米鐵氧體:石墨:�；⒅�:浮石:鋼纖維:減水劑:分散劑:水=65:20:15:3:3:14.6:124:12.7:1:0.6:50。
[Abstract]:With the development of digital communication system and the wide application of various electronic devices, electromagnetic radiation pollution has become a new social hazard. In view of the deteriorating electromagnetic environment and the requirements of military stealth and protection, it is of great significance to study the cement-based composite absorbing materials with wide band, high efficiency and satisfying the structural load requirements. Aiming at the problems of low absorptive efficiency, high quality, high cost, poor stability and low bearing capacity of cement based composite absorbing materials, this paper makes a comprehensive design from the aspects of impedance matching, wave absorbing efficiency and structure carrying capacity. The preparation method of nanometer CoFe2O4 absorbent was discussed at first, and then the kinds of admixture, porous aggregate, absorbent, fiber and the strength of high performance cement composite absorbing material were discussed. The influence of resistivity and absorbing property. The results showed that the raw materials cobalt nitrate, ferric nitrate and sodium hydroxide and dispersant polyvinyl alcohol were ball-milled for 1 h and then calcined at 700 鈩，

本文編號(hào)：2295431