本文選題：等離子體浸沒離子注入與沉積　切入點(diǎn)：TiBN納米復(fù)合薄膜　出處：《哈爾濱工業(yè)大學(xué)》2017年博士論文

【摘要】：隨著國防裝備制造產(chǎn)業(yè)的高速發(fā)展,一些關(guān)鍵機(jī)械零部件必須在高溫、高速條件下進(jìn)行服役,在這些零件表面制備出具有抗高溫氧化、低摩擦系數(shù)和耐磨損的表面強(qiáng)化層是滿足這類工況的關(guān)鍵。傳統(tǒng)固體潤(rùn)滑材料,如二硫化鉬、類金剛石等,在高溫條件下易發(fā)生氧化分解,不能滿足這類需求。六方氮化硼(h-BN)的抗高溫氧化溫度上限可達(dá)900°C,并在寬溫域內(nèi)均能保持恒定的低摩擦系數(shù),在高溫固體潤(rùn)滑領(lǐng)域體現(xiàn)出很大的應(yīng)用潛力。但是,目前含有h-BN的固體潤(rùn)滑涂層的制備方法主要為粉末冶金或激光熔覆,很難實(shí)現(xiàn)精密零件表面的鍍膜。通過物理或化學(xué)氣相沉積技術(shù)制備的BN基復(fù)合薄膜其氮化硼主要為立方相,不具備低摩擦系數(shù)的特征,無法實(shí)現(xiàn)高溫固體潤(rùn)滑的目的。由于h-BN屬于絕緣材料,直接通過陰極弧方法無法形成等離子體,本研究將Ti與h-BN粉末進(jìn)行混合,通過冷壓成型、真空熱燒結(jié)的方法制備了TiBN復(fù)合陰極。研究結(jié)果表明,當(dāng)h-BN含量控制在40wt.%以內(nèi)時(shí),Ti-BN復(fù)合陰極具有良好的導(dǎo)電性能。隨著h-BN含量的提高,Ti-BN復(fù)合陰極電阻明顯增加,且陰極相對(duì)密度呈下降趨勢(shì)。采用等離子體取樣質(zhì)譜儀測(cè)量了Ti-BN復(fù)合陰極放電等離子體的特征參數(shù),研究了陰極成分、磁導(dǎo)管角度、氣壓和電流對(duì)等離子體分布規(guī)律的影響。研究結(jié)果表明,Ti-BN復(fù)合陰極放電過程形成的等離子體中主要包含Ti~+、Ti~(2+)、BN~+離子等。與45°磁導(dǎo)管相比,這些離子在90°磁導(dǎo)管中的損失率要高1倍左右;當(dāng)氣壓在0.1Pa到1.0Pa范圍內(nèi)變化時(shí),Ti~+和BN~+離子密度與氣壓的關(guān)系呈現(xiàn)高斯分布,在0.3Pa時(shí)離子密度最高,采用該工作氣壓有利于提高TiBN納米復(fù)合薄膜的沉積速率;當(dāng)電流增大時(shí),離子密度明顯增加,但是當(dāng)平均電流提升至14A后,離子密度基本不隨電流的增大而增加,而且平均電流的繼續(xù)提高將導(dǎo)致弧光放電過程中大顆粒數(shù)量急劇增加。采用Ti-BN復(fù)合陰極以及等離子體浸沒離子注入與沉積(PIIID)工藝制備了TiBN納米復(fù)合薄膜。結(jié)果顯示,隨著薄膜中B含量的提高,薄膜內(nèi)部非晶含量增加,同時(shí)納米晶尺寸減小,紅外傅立葉光譜和X光電子能譜分析結(jié)果表明,薄膜內(nèi)的B和N之間化學(xué)鍵的雜化形式是sp~2雜化。高分辨透射電鏡結(jié)果表明TiBN納米復(fù)合薄膜為非晶包裹納米晶結(jié)構(gòu),納米晶成分主要為Ti N,而非晶成分包括BN和Ti O2等。此外,TiBN納米復(fù)合薄膜斷面結(jié)構(gòu)均出現(xiàn)了不同程度的自分層現(xiàn)象,這主要是由于薄膜中納米晶尺寸變化造成的。隨著薄膜中B含量的提高,納米晶中部分出現(xiàn)了h-BN相。室溫條件下所有TiBN薄膜的摩擦系數(shù)均較小,介于0.15~0.3之間,而且隨著薄膜中BN含量的提高,薄膜摩擦系數(shù)逐漸降低,15wt.%含量的Ti-BN復(fù)合陰極所制備的薄膜具有最佳的耐磨性能。TiBN納米復(fù)合薄膜的高溫氧化實(shí)驗(yàn)結(jié)果表明,該復(fù)合薄膜在低于800℃時(shí)仍能保持較低摩擦系數(shù),介于0.2~0.35之間,但薄膜表面出現(xiàn)了明顯的氧化物;當(dāng)溫度達(dá)到1000℃時(shí),薄膜出現(xiàn)了不同程度的崩裂。
[Abstract]:With the rapid development of national defense equipment manufacturing industry, some of the key mechanical parts must be in high temperature, high speed under the condition of service in these parts of the surface were prepared with high temperature oxidation resistance, low friction coefficient and wear resistant surface strengthening layer is the key to meet these conditions. The traditional solid lubricating material, such as diamond, molybdenum disulfide, etc. that oxidation easily occurs in high temperature conditions, which can not meet the needs of six. Boron nitride (h-BN) high temperature limit oxidation temperature can reach 900 DEG C, low friction coefficient and in a wide temperature range can be kept constant, reflecting the great potential in the field of high temperature solid lubricant. However, solid the lubricant coating containing h-BN preparation method for powder metallurgy or laser cladding coating, it is difficult to achieve precision parts. The surface by physical or chemical vapor deposition technology for preparation of BN composite thin films Mainly for the cubic boron nitride, does not have the characteristics of low friction coefficient, cannot achieve high temperature solid lubrication. Because h-BN belongs to insulation materials, directly through the cathode arc method to form plasma, this study will Ti and h-BN powders were mixed by cold pressing, TiBN composite cathode preparation method of vacuum sintering thermal system research results show that when the content of h-BN within 40wt.%, Ti-BN composite cathode has good conductive properties. With the increasing content of h-BN, Ti-BN composite cathode and the cathode resistance increased significantly, the relative density decreased. The characteristic parameters of Ti-BN composite cathode discharge plasma was measured by plasma mass spectrometer sampling, on the cathode composition, magnetic catheter angle, effect of pressure and current on the plasma distribution. The results show that the Ti-BN composite cathode discharge plasma process 涓昏鍖呭惈Ti~+,Ti~(2+),BN~+紱誨瓙絳，

本文編號(hào)：1656335