(1. 第二炮兵工程學(xué)院501室,西安 710025;
2. 第二炮兵駐孝感地區(qū)軍代室,孝感 432100;
3. 西安交通大學(xué) 材料科學(xué)與工程學(xué)院,西安 710049)
摘 要: 應(yīng)用噴霧造粒技術(shù)對(duì)納米β-SiC/LBS復(fù)合吸波粉末進(jìn)行團(tuán)聚造粒,采用超音速火焰噴涂工藝制備高溫納米復(fù)合吸波涂層,并對(duì)復(fù)合涂層性能進(jìn)行研究。結(jié)果表明,顆粒狀β-SiC彌散在半熔融狀態(tài)的LBS中形成涂層。涂層與基體的結(jié)合強(qiáng)度為8.46 MPa,拉伸過程中,涂層從內(nèi)部撕裂,并表現(xiàn)為脆性斷裂。與普通陶瓷吸波涂層相比,復(fù)合涂層的吸波性能得到擴(kuò)展;隨著涂層厚度的增加,復(fù)合涂層對(duì)電磁波的衰減能力將從高頻向低頻移動(dòng)。受到涂層抗拉強(qiáng)度的限制,復(fù)合涂層的厚度應(yīng)該小于1 mm。納米β-SiC含量(質(zhì)量分?jǐn)?shù))為46%時(shí),復(fù)合涂層的電磁波反射率系數(shù)達(dá)到−13 dB;當(dāng)在涂層厚度相同而微波頻率大于14 GHz時(shí),復(fù)合涂層的電磁波反射率系數(shù)均小于−10 dB。數(shù)值模擬結(jié)果表明,當(dāng)β-SiC質(zhì)量含量為46%時(shí),復(fù)合涂層的吸波性能最佳。
關(guān)鍵字: 吸波涂層;熱噴涂;等效媒質(zhì)理論;結(jié)合強(qiáng)度;小波分析
(1. Xi’an Research Institute of Hi-Tech, Xi’an 710025, China;
2. Staff of Military Deputy Xiaogan, Xiaogan 432100, China;
3. School of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China)
Abstract:The nanometer agglomerate β-SiC/Li2O-B2O3-SiO2 powders were prepared by spraying granulation. The composite absorber coatings were fabricated by high temperature velocity oxygen fuel(HVOF) thermal spraying technique, and the performances of the coatings were studied. The results show that the microstructure of the coatings is constructed with the SiC particles dispersing in the melting LBS phases. The tensile strength of the coatings is 8.46 MPa, and the crack occurs in the coatings and takes on the brittle rupture in the course of the tensile stress. The microwave reflectivity of the coatings is expanded, compared with that of normal absorber ceramic coatings. When the thickness of the coatings increases, the microwave reflectivity shifts from high frequency to low frequency. However, the thickness of the coatings should be less than 1 mm restricting with the tensile strength of the coatings. When the mass fraction of β-SiC is 46%, the microwave reflectivity coefficient of the coatings can arrive to −13 dB. Especially, at the same thickness of the coatings, when the microwave frequency is larger than 14 GHz, the reflectivity coefficients are all less than −10 dB. The simulated result shows that the microwave absorbing performance of the coatings is the best when the mass fraction of β-SiC is 46%.
Key words: absorber coatings; thermal spray; effective medium theory; tensile strength; wavelet


