SiC/AIN of Fu of CF successive besmear

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Foreword brings to bear on in CF surface coating in order to raise its heatproof oxidisability, improve the interfacial behavior of the CF in composite material and base material, it is the task of fetching attention all the time. One of technologies that in recent years development comes out [1] is to use organic polymer pioneer body solution macerate is firing craft, bring to bear on in carbon fiber surface inorganic coating, include to use get together carbolic silicon alkyl, get together boracic nitrogen alkyl, get together alkyl of boracic silicon nitrogen or get together alkyl aluminous amine is raw material, wait in SiC of Fu of besmear of carbon fiber surface, BN, SiC10 BN or AlN respectively. Of successive besmear Fu carrying out also is one of research heat: Wait like Wang Yuqing [2] is raw material with H2 and CH3SiCl3, use law of deposit of chemical gas phase to be in SiC of fiber surface Tu Fu, be in respectively in its device carbon fiber pretreatment paragraph with deposit paragraph protection of the gas that use Ar: Li Hualun " with Sol, Gel law is in SiO2 of Tu Fu of carbon fiber surface, different share is Ar respectively in its device, compress air or ammoniac gas atmosphere; J. K. Yu [4] uses CVD method, in the airtight equipment below Ar protection, different aeriform raw material introduces in different level, in carbon fiber apparently the gradient coating that brought to bear on to include C, C/SiC, SiC/Si, Si. J. K. The coating fibrous function of Yu is apparent the result that excel other covers, but traversal speed of the fiber when besmear Fu is less than 0.

01mmin-1. The uses SiC/AIN of organic and precursory system research that place of our early days has makes clear as a result [5] : Get together carbolic silicon alkyl and get together the chemical reaction when second radical aluminous amine mixes, make splitting decomposition of mixture pioneer body firing rate is apparent rise: Accordingly, use mixture pioneer body to bring to bear on in carbon fiber surface SiC/AIN coating, be expected to get compact coat more easily. The article covers the plant of successive besmear Fu that we design with proper motion, use polymer pioneer body solution macerate is firing craft, treatment gives the carbon fiber that has SiC/AIN coat, evaluated coating to improve CF function and CF, the effect of the intensity of AL compound silk. 1 experiment 1.

Equipment of 1 successive Tu Fu and the equipment of successive Tu Fu that craft place designs include main body, drive, control, heat, the part such as refrigeration and protective gas district, the graph is shown 1 times for equipment main body. Electric machinery drives G canister, the carbon fiber on drawing A canister falls in nitrogen protection with speed of 6m · Min-1 ordinal through pool of C of furnace of macerate pool B, pre-burning, macerate E of furnace of D, pre-burning is mixed sintering furnace F, implementation besmears continuously Fu. Intensity holds a when next moving fiber that does not add solution, electric stove not to warm up in macerate pool rate in 99 ％ above. Graph 1 press document the method of 5, make SiC/AlN mix solution of precursory body toluene, precursory body total chroma is less than 2 ％ , among them Si/AL compares again for 8: 2. Afore-mentioned solution are added in two macerate pool below nitrogen protection, heat electrify of each electric stove to book temperature (E of furnace of pre-burning furnace C, pre-burning and sintering furnace F are respectively 300, 500 with 1000 ℃ ) , start successive plant next, produce Japan T300 carbon fiber to machine the carbon fiber that has SiC/AIN coat. 1.

2 fibrous token (1) configuration and exterior analysis: Use former fiber and coating fasciculus respectively silk and monofilament sample do bend test, in the observation on HI-TACHIH-8000 electron microscope former fiber surface, coating fiber surface and classics relapse to the turn folds coating fiber and cause the form appearance of the coating of damaged, use EDAX, 900 model can the elemental content of surface of coating of chart appearance analysis. (Tensile strength of 2) average monofilament: Use YG, 100 model puissant appearance measures monofilament fiber electron the drawing bear value of fiber monofilament, sample places span (fiber length) 20mm, span is 20 grams, drop speed is 2mmmin-1, reoccupy does minute of feet to measure a diameter, computation gives monofilament tensile strength. Each bundles of fiber takes 40 monofilament to make appearance, after measuring, use at computation the significant result that average monofilament draws intermediate strength not less than 25. (3)TG/DTA analysis: TG/DTA analysis heats up analyzer in Dupont9900 and Dupont1090 aspirant travel, atmosphere of air of going from place to place, warm up speed Min-1 of 20 ℃ · , measure temperature limits to come for room temperature 1000 ℃ . (4) heats up the impact that reveals mechanical to fiber performance: Be in a series of former fiber and sample of coating carbon fiber perpendicular the 1 heat with parallel of the course in air atmosphere exposes the position that draws intermediate, the monofilament that measures them next draws intermediate strength, improve fiber in order to evaluate coating the effect of heatproof oxidisability. Heat exposes an experiment to undertake below two kinds of conditions. A. Time heat exposes: Mix a group of former fiber below different temperature parallel of sample of fiber of a group of coating heats two hours, measure monofilament tensile strength next. B. Calm tepid expose: 310 ℃ issue will former fiber and parallel of coating fiber sample to heat 30 hours to mix 60 hours, measure monofilament tensile strength next. (5) and aluminous compound experiment [note] : It is former carbon fiber and coating fiber respectively below supersonic oscillation pass aluminous fluid and make so that the diameter is about 0.

The successive and compound silk of 5mm (bulk mark is 50 ％ ) about, cut short hind measure its tensile strength with the span of 20cm. Compound silk measures avery kind of 20 sample, take average. Nextpage2 test result and discuss 2.

Configuration of 1 coating fiber and surface analyse exterior of macroscopical coating carbon fiber to shine, adhesion phenomenon is not had between silk and silk. Coating fibrous Shusi and monofilament all can curve aleatoric angle to any direction like former fiber and do not break off, observe with the electron microscope via be close to 180 ° the turn folds the following sample 3 times to did not see coating damaged, show coating fiber maintained former fibrous complaisant the character that can braid. Graph 2 reach coating fibrous for former fiber electric lens photograph, can see level off of surface of coating carbon fiber is smooth, coating is complete and even, do not have between fiber and fiber " build the bridge " (Bridging) phenomenon: Can reckon from breakage coating ply is less than 1 μ M. Of coating surface can the weight that chart analyses the Si in making clear coating as a result and Al is compared for 80.

5: 18.

5, with precursory body in agree basically. Graph 22.

Average monofilament tensile strength is former carbon fiber of tensile strength of 2 average monofilament 3835MPa, and average monofilament tensile strength is coating carbon fiber 3788MPa. The intensity after besmear Fu maintains rate for 98.

6 ％ . 2.

3TG/DTA analysis compares former fiber and coating fibrous to heat up analytic chart to pursue as a result, curve of the TG of knowable latter, DTA all moves to high temperature direction, and the fiber combustion radiative peak in DTA broadens become blunt, explain coating improves the result of the heatproof oxidisability of carbon fiber. But combustion process of fiber of DTA curve specification is not stable. When assaying fits pattern, heat needs to cut fiber small Duan Zaijuan to become small group, because the end panel of clipping does not have coating, so hot analysis cannot show the thermal stability of coating carbon fiber well and truly as a result. 2.

The impact that 4 heat reveal pair of fiber intensity (the monofilament tensile strength of each sample and heat expose the former fiber after 1) times heat is exposed and coating fiber the experimental curve that temperature concerns. The tangent extrapolate of two parts curve reachs the from beginning to end that produces monofilament tensile strength to change apparently intersect, the fiber that is the temperature definition of nodical correspondence heat to expose 2 hours is heatproof oxidation temperature Th. Th of former fiber is 330 ℃ , and Th is coating carbon fiber 680C, both differs a value to be 350 ℃ . Described coating mensurably to improve fiber thereby the effect of heatproof oxidisability. (2) exposes 30 hours to mix 60 hours in the heat below 310 ℃ hind, former fibrous intensity is respectively 3456 with 2994MPa, each dropped 10 ％ and 22 ％ ; And intensity of Xu layer fibrous is respectively 3757 with 3745MPa, drop only about 1 ％ : Showing thread of the coating below the temperature that drops quickly in intensity of former carbon fiber basically is stable. 2.

The average tensile strength of 5 as former as the intensity of aluminous compound silk carbon fiber and aluminous compound silk is 770MPa, coating carbon fiber and aluminous compound silk are average tensile strength is 1090MPa. The tensile strength of oversight aluminium, can bless calculates, this highest intensity of compound silk is 1500MPa about. So, former fiber and aluminium are compound, intensity maintains rate for 51 ％ ; Coating fiber and aluminium are compound, intensity maintains rate for 73 ％ , latter comparing is former tall 40 ％ . This makes clear in as compound as aluminium when, siC/AIN coating prevented the reaction between carbon fiber and aluminium effectively, improved the interfacial behavior between both. The device that article place design assembles 3 conclusion can carry out solution macerate steadily with rapidder rate successive besmear Fu (can machine sheet every year bundle 400Kg) of T30 carbon fiber. Use polymer pioneer body solution macerate is firing craft, brought to bear on in carbon fiber surface the SiC/AIN coating with smooth level off. The Si/Al in coating is compared with precursory body in agree basically. Machines coating carbon fiber maintained former fibrous complaisant can braid gender and mechanical intensity, coating makes fibrous heatproof the intensity pulling intermediate of oxidisability and fiber and aluminous compound silk has bigger rise. On the foundation of afore-mentioned jobs, can form the ability that batch machines, and preparation goes out have multilayer the coating of coating, gradient coating; Yu Wei, need in order to get used to what the function between the matrix in different composite material and intensifier transfers to match with the interface. CNC Milling