Ü Õ I ® CnullSiC¯ Ú Ñ Â ¸ + ¥ k ù î nullEXPERIMENTAL INVESTIGATION ON THE FATIGUE CHARACTERISTICSABOUT HIGH TEMPERATURE OF PLAINnullWOVEN CnullSiC COMPOSITEñ µ nullnull1, 2 null ` l 1 null null ¢ null U 1, 2 null null Û null . 1,2 null null - Å ~ 1 null null Ù null \ 1(1. 西北工业大学无人机特种技术重点实验室, 西安 710072)(2. 西北工业大学航空学院, 西安 710072)CHENG QiYou1, 2 null TONG XiaoYan1 null ZHENG Xiang1, 2 null ZHOU Jun1, 2 null YAO LeiJiang1 null LI Bin1(1. NationalLaboratory of UAV SpecialTechnology, NorthwesternPolytechnical University, Xinullan 710072, China)(2. Schoolof Aeronautics, NorthwesternPolytechnical University, Xinullan 710072, China)K 1 null ¹ ù î 2D Ü Õ I ® CnullSiC¯ ¥ Ú Ñ Ä Â ¸ ? , ¨ Instron8801A â º  ¸ k É Â ¸ k ,  ¸ k ¥ V ñ Ï ,] H ¨ Ú Ñ Ä Ì â " d k " É Ú Ñ Ä bÚ Ñ Â ¸ k ª , ¨ á í È 0 A ± ä k " g ¥ ± 4 · É 1 s bk ? C , k " ¥  ¸ p Û ¥ 9 F 7 A ÷ ® , Ä 8 i ¥ Ì â/  ¸ K ® b ï £ Ü ¥ Ú ® k " ¥ Ä ñ Y ü A , ï £ Ü ® ,k " = ¥ Ä ñ ® b£ s â Ú ¥ Ì â k " p ü A 1 ® , ¥ V ë p ª Ä E s ø × , O ï £ Ü ® ,£ s â Ä ¹ Y v b1 o M null CnullSiCnull Ü Õ I ® null Ú Ñ null  ¸ k null å ÄÏ m s Ë | null TB33null TG115.57Abstractnull To study fatigue property of 2D plainweave CnullSiC compositematerial at high temperaturewith oxidation environment, aconstant amplitudetensionnulltension fatigueexperiment is taken. During the experiment, the system of high temperature and oxidation isused to oxygenizethespecimen. After the experiment, the scanningelectron microscope( SEM) is usedto investigatethemicrostructuresof specimens. Theresults oftheexperiment show that thefatiguelifeof specimen decreases evidentlywiththe increaseof load andoxidanulltive property of environment. The stress influences on the degree of oxidation. The higher stress is, the more serious the oxygenation.With the increaseof theratioof watervapor, thefatigue lifeof specimen decreases and the oxidation of coating becomesmoreserious. Ifthe stress is lower, the influence of water vapor on oxidative property is more serious.Key wordsnull CnullSiC; Plainnullwoven; Hightemperature; Fatigue experiment; Damage evolvementCorrespondingauthor: CHENG QiYou, Enullmail: qy-cheng@163. com, Tel: + 86null29null88451161, Fax: + 86null29null88451160The project supported by theNational Natural ScienceFoundation of China (No. 10372081) .Manuscript received 20080825, in revised form 20080929null null ý( L ¯ [ v a r¥ k " k ª É á % k ,© ç : Å F < bV 2null Õ Ì â ¥ 8 Tab. 2null The parameter of gasÌ âEnvironmentAr O2 H2OÌ â AEnvironment A81. 2% 12.8% H2Onull 37 ! (6%)Ì â BEnvironment B47. 8% 17.3% H2Onull 72.6 ! (34. 9%)m 2null Ú Ñ V e L V k " ½ U i mFig. 2null Thesystem of high temperature3null k ² T s 5q k " É 1 300 ! b Ì â / ¥ _ %k ,¤ k " ¥ Ü ( F < ¹ 300 MPa,1 È Ñ Ú 12% b3.1 null Ú Ñ Â ¸ ?m 3ó ] Ì â Ï k q ¥  ¸ p w L , V mÏ V [ A ,k " ¥  ¸ p Û ¥ 9 F 7 A ÷ ® , Ä 8 i ¥ Ì â B/ ¥ k "  ¸ K üA ® ¿ Ì â A bm 3null Ú Ñ £ ª K Ì â  ¸ p w LFig. 3null The fatigue lifeof specimen in high temperature environment90 MPa/ , Õ Ì â / ¥ k " ( à ,k " Ϥ Ï ª ,É È Ñ / % k , % w L  m 4îU b V [ A , Ì â BÏ k " ? ¥ / 1 Ì â Ak" ? ¥ / 1 â ] ,Ì â A Ï k " ¥ : Å < ¹230.5 MPa,Ì â Bk " ¥ : Å < ¥ Ç ¹ 188.2MPa, ^ y ¹ Ä 8 i ¥ Ì â B/ , = 8 »null 820 null null null null < null null 2010 M nullm 4null 90 MPaÚ Ñ Ì â  ¸ ª k " % w LFig.4null Thetensile performance of specimen after fatiguetestin high temperature environment¥ Ä å 1 ø × ,7 = 8 » ¥ Ä å ñ ¿ : Å < ¥ Y d È ü A ,8 » Ä ¥ 1 è Ú , : Å < ® b3.2 null  ¸ Ä ¹ ¥ Y ¸ ¿ Ä ¥ Y d È ü A ,y ¹ ï ¥ T ¨ / ,ð µ ¥ Å ! Õ ö $ z ,] H Î ö Á3 ¥ Õ ,i ® N Y 8 » ¥ Ä ¹ ,n 5 ,p ª 8 ¥ Õ $ 7 ª ,p ª V ë î ¥ ÄA ¹ ? A Õ , ¹ _ = Û ,Y V Õ r Õ ¸ ª ,, V ¯ Ï ¥ d _ M Vë Û ,i O Ð M ¥ Ä Ä É Q ;i O ï T¨ / , _ Õ _ - Z ,i : _ Ê | t Õ , Õ$ 8 » B ó 。