外文翻譯---碳結(jié)構(gòu)和固體顆粒侵蝕的保護(hù)高度多孔炭碳復(fù)合保溫材料的使用-材料科學(xué)-預(yù)覽頁(yè)
【正文】 atter may bee entrained in the gas ?ows, and impingement with the insulation may result in material removal. In the challenging environment of gas quenching, there is a requirement for erosion protection of the CBCF by the use of higher density carbonbased coating and cladding , ductile and brittle materials exhibit different erosion characteristics。. For this material, two mechanisms were effective: disruption of the graphite ?akes, which are mainly held together by mechanical locking, and a ploughinglike mechanism. The addition of a thin CVD carbon layer to colloidal graphite paint improved performance, whereas the erosion resistance of the graphite foil was slightly degraded as the CVD layer was too thin to prevent the ploughinglike mechanism. 1. Introduction A class of highly porous carbon— carbon (C— C) posites, with low densities in the range — Mg m\3, are utilized as thermal insulation in vacuum and inertgas furnaces at temperatures up to2800 176。, where the erodent stream is perpendicular to the erosion surface, and brittle fracture was the predominant mechanism of material removal. The exception was the graphite foil material which displayed maximum erosion at an angle of incidence of 60176。 Hall CBCF is used in furnaces employed in high technology applications such as singlecrystal growing (for example, silicon or gallium arsenide) or metal heat treatment. The heat treatment of metals, such as tool steels, is increasingly carried out in furnaces that utilize gas quenching (typically nitrogen is used) [12, 13]. The gas quench may be used to reduce the turnaround time of batch processes or as an integral part of the heattreatment regime. The advantage of gas quenching during heat treatment, as opposed to an oil quench, is that the cooling rate can be controlled。C under a reduced. 2. Experimental procedure . Materials The CBCF used as the substrate was a standard mercial material (density Mg m\3) manufactured by Calcarb Ltd. The coating and cladding materials were applied to the xy plane of the CBCF substrate (see the schematic diagram of CBCF structure in Fig. 1)。 mm。, 75176。 however, where charging of retained silica erodent was evident in the eroded samples, they were splutter coated with gold. 3. Results and discussion . Microstructure The structure of CBCF insulation material is shown in Fig. 1。 依賴(lài)性侵蝕率的 發(fā)生率 的角度考察了從微觀(guān)結(jié)構(gòu)與機(jī)制的材料 切 除率作為 SEM 觀(guān)察 的 結(jié)果 。 ， 從流的垂直于表面的侵蝕和脆性斷裂是優(yōu)勢(shì)機(jī)制的材料切除 。 除了薄層膠體 CVD 碳石墨涂料性能的改善 ， 而腐蝕能力的石墨鋁箔略退化為 CVD 層太瘦了防止 像耕田一樣的 機(jī)制 。 絕大多數(shù)的成交量復(fù)合由互聯(lián) 網(wǎng) 和光纖網(wǎng)絡(luò)是保稅交叉運(yùn)用離散區(qū)域的纖維碳矩陣而不是一個(gè)連續(xù)的矩陣。 (1997 年查普曼大廳 CBCF 用于爐采用高技術(shù)應(yīng)用 ,如單晶增 長(zhǎng) (例如 ,硅或砷化鎵 ) 或金屬熱處理。在充滿(mǎn)挑戰(zhàn)的環(huán)境 下 的氣體淬火 ,有一個(gè)要求 CBCF 侵蝕的保護(hù)使用更高密度的碳基涂層和熔覆材料 。 的 金屬 。 整體 目標(biāo) 的 進(jìn)程 都是與顯微組織侵 蝕現(xiàn)象的數(shù)據(jù) 相關(guān)的， 通過(guò)一個(gè)機(jī)械的方法材料包括纖維材料有限公司。致密化將在大約 1100176。涂層和熔覆材料 測(cè)定 —— 在本文中 都是碳基及它們?cè)诒?面 涂層材料 ， 是指那些 性能 自行 以 CBCF 襯底 ,就像 推保稅通過(guò)一輛車(chē) —— 波蘭特 水泥。 組成的膠 ， 密度高碳 碳復(fù)合材料作熔覆壓力 5 kPa(注意 ,多粒子 中碳的多孔介質(zhì)內(nèi)部的是有時(shí)被稱(chēng)為化學(xué)蒸氣滲透 )。 侵蝕測(cè)試 多粒子 侵蝕測(cè)試進(jìn)行氣體 —— 爆炸類(lèi)型 測(cè)定 ,被描述為卡特。目標(biāo)標(biāo)本 表面 尺度 25mm、 、 5mm。粒子的速度是 按年代算 的 ,發(fā)現(xiàn)的 表面 攝像技術(shù)在這個(gè) 方位 。 、 60176。根據(jù)這些 實(shí)驗(yàn) 的梯度 ， 這個(gè)侵蝕率 ,在數(shù)量上表現(xiàn) 為 大規(guī)模 被切除 。 另一個(gè)包覆材料石墨箔 控制 是通過(guò)壓縮剝落石墨薄片在滾動(dòng)操作。但是 ,充電的 狀態(tài) 從 硅膠中 顯侵蝕樣本。然而 ,由于高孔隙率的 原因 和相互聯(lián)系的本質(zhì)在 CBCF 基質(zhì)孔隙度 ,一些油漆滲透到深度 600lm。這個(gè)過(guò)程可以產(chǎn)生一層致密熱解碳約 5lm厚表面的油漆涂料 ,具有小的 部分 C3 CC FMI 的復(fù)合是由聚丙烯腈 (PAN)前體碳纖維布 ,它是大約 毫米厚。
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