外文翻译---碳结构和固体颗粒侵蚀的保护高度多孔炭碳复合保温材料的使用-材料科学(编辑修改稿)

外文翻译---碳结构和固体颗粒侵蚀的保护高度多孔炭碳复合保温材料的使用-材料科学(编辑修改稿)内容摘要：

y means of a car bonizing cement. Calcoat and Calcoat M are colloidal graphite paint coatings that were applied to the CBCF substrate by brushing. The material was subsequently heat treated at 900 176。 C in nitrogen to carbonize the resin constituent of the colloid. Higher density carbon— carbon posites (39。 Mg m\3) used as cladding pressure of 5 kPa. (Note that the CVD of carbon in the interior of a porous medium is sometimes termed chemical vapour infiltration, CVI.) Another cladding material was graphite foil which was produced by Toyo Tanso by pressing exfoliated graphite flakes in a rolling operation [23]. The foil is flexible in nature and is predominantly held together by mechanical locking, as no binder is used. Further samples were produced by subjecting the Calcoat coating and the graphite foil to a CVD treatment (samples designatedCVD in Table I) for a period of 75 h under the conditions described above. A more extensive descrip tion of the materials will be forthing in the dis cussion on the microstructures. . Erosion testing Multiparticle erosion tests were performed on a gas blast type rig, as described by Carter et al. [24]. In this apparatus the erodent particles enter the rig via an aperture in the base of an open hopper. A venturi fitted in the system allows the particles to be entrained in the pressed air flow. After passing through a nozzle with an 8 mm internal diameter, the particles strike the target at a standof distance of 40 mm. The target specimens had nominal dimensions 25 mm。 mm。 5 mm. The erodent used was angular equiaxed silica sand obtained from Hepworth Minerals and Chemicals Ltd, Redhill, UK. The erodent was sieved to particle sizes between 150 and 300 lm, the mean size (by weight) was 230 lm which was found by a laser difrac tion method (Mastersizer 1005, Malvern Instruments Ltd, Malvern, UK). The velocity of the particles was 6 m s\1, found by the streaking camera technique at the position of the target. This method involved expo sing the film for a known length of time and measuring the length of the line that the particle produces on the film. Erosion tests were carried out at angles of 30176。 , 45176。 , 60176。 , 75176。 and 90176。 . Generally, the samples were impacted by a fixed mass of erodent, then cleaned and reweighed. This process was repeated and the accumulated mass loss plotted against the accumulated mass of erodent. The erosion rate, expressed in terms of mass removed perunit mass of erodent, was calculated from the gradient of these plots. However, in the case of the lowdensity CBCF substrate material, which was investigated for parison purposes, a significant mass of erodent perated and was retained within the porous structure of the posite. When calculating the erosion rate, the mass of this perated erodent must be taken into account and therefore the erosion rate was found in the following manner. Each sample received only a single dose of erodent. The total mass change of each sample, *188。 , is equal to the mass of positepressure of 5 kPa. (Note that the CVD of carbon in the interior of a porous medium is sometimes termed chemical vapour。