复合材料课件

nullnullComposite Material Science Jiacheng Gao (gaojch@cqu.edu.cn) 2010-10-10 Main ReferencesMain References1、Composite Materials Science and Application----Deberah D. L. Chung（Springer,2009） 2、复合 材料 关于××同志的政审材料调查表环保先进个人材料国家普通话测试材料农民专业合作社注销四查四问剖析材料 力学----矫桂琼（西北工业大学出版社,2006） 3、复合材料新进展----刘雄亚（化学工业出版社,2007） 4、金属基复合材料----赵玉涛（机械工业出版社,2007）Chapter 3 mechanical properties of composite materialsChapter 3 mechanical properties of composite materials1 Fundamental principle 2 Calculate models El = K[EfVf + Em(1-Vf)] Eta = EfEm/(EfVm + EmVf) , Etb = EfVf + Em(1-Vf) υl = K[υfVf +υm(1-Vf)], υ t =υ l Ef/El Ga=GfGm/(GfVm+GmVf), Gb = GfVf + Gm(1-Vf) 2 Calculate models2 Calculate models2.5 strength of continuous fiber composite materials (σ) Longitudinal strength (σlu) Deformation process of composite material 1) fiber & matrix, elastic deformation σlu = σfVf +σm(1-Vf) = EfεfVf + Emεm(1-Vf)2 Calculate models2 Calculate models2) fiber elastic, matrix plastic σlu = σfVf +σmε(1-Vf) 3) fiber & matrix plastic little 4) composite material fracture σlu = σfuVf +σmu(1-Vf)2 Calculate models2 Calculate modelsCritical fiber volume fraction (Vf) Pf/Pm = EfVf/Em(1-Vf) Vf=constant, Ef/Em↑, Pf/Pm ↑ Ef/Em=constant, Vf↑, Pf/Pm ↑ Vf = (σu-σm)/(σf-σm) σu ↑, Vf↑; σf↑, Vf↓nullC: Vf＜Vfc, σu＜σm E: Vfmin = (σu-σm)/(σu+σf-σm) Vf＜Vfmin, matrix Vfmin＜Vf＜Vfc, matrix and fiber Vfc＜Vf, fiber Vf: 91%, 80%, 30-60%, … Al＞0.8, Cu＞2.4, Ni＞3.6, 316L＞4.1…2 Calculate models2 Calculate modelsLongitudinal compress strength (σcu) 1) T-C instability stress of fiber σcu =2KVf[VfEmEf/3(1-Vf)]1/2＞σ 2) S instability stress of fiber σcu= Gm/(1-Vf)＞σ 3) instability stress of matrix σcu= σmp(Vm+EfVf/Em)≈σ2 Calculate models2 Calculate modelsTransverse strength (σt) Pull, σm＞σi, σt =σi σm＜σi, σt =σm Compress, σt =σm Shear, τl∥ =τm, τt⊥ =τfVf +τmVm θ ?3 Another study methods on composite material mechanical3 Another study methods on composite material mechanicalWeibull statistics FDM & FMM Eshelby model … 3.1 statistics method (Weibull)3.1 statistics method (Weibull)Fiber S=1-exp(-B), B=∫Lu(σ)dL, u(σ)=kσm ∴s=1-exp(-kσmL) Make k=1/σm ∴s=1-exp[-L(σ/σ0)m] Cauchy: F(x)=exp[-(σ/σ0)2β] ∴s=1-exp[-L(σ/σ0)2β] σ1/σ2=(L2/L1)1/m, σf=σ0Γ(1+1/m)3.1 statistics method (Weibull)3.1 statistics method (Weibull)A bunch of fibers σn=P/n, σn-1=P/(n-1), σn-2=P/(n-2)… , σn-i=P/(n-i)… Coleman: σmax= σ0m-1/m ∴σfb=σ0(1/me)1/m Composite materials ∴σfc=σf(n/me)1/m3.2 FDM &FMM3.2 FDM &FMM ①建立物理模型②确定数学方程③空间离散化④计算各体积元⑤建立方程组⑥解方程组Eshelby modelEshelby model??How to found and apply the calculate model of composite material mechanics ?null4 Physical-chemical properties of composite materials4.1 density 4.2 thermal 4.3 combustion 4.4 photics 4.5 corrosion null复合材料中，基体或增强体量常以质量百分率 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 示，必须将质量百分率换算成体积百分率，才能应用复合规则来估算复合材料的密度。 4.1 densityρc——density of composite materials ρm——density of matrix ρf——density of fiber or particle Vf——volume fraction of fiber or particle 复合材料的最基本物性nullnull(1)null4.2 Thermal properties热性能热基础物性耐热性热膨胀系数导热系数 比热热功能复合材料的最重要性质与力学性能并列为结构复合材料最重要的特性nullα ——热膨胀系数； Vf——增强体的体积分数； 角标c、m、f分别代表复合材料、基体和增强体。4.2.1 basic thermal properties基本上可按复合规则加以估算： 一般无机增强体的热膨胀系数较基体的要小，所以，无机增强复合材料的热膨胀系数要较纯基体材料的小。 null聚合物、填料及其复合材料的热膨胀系数(×10-5)null膨胀系数的各向异性 由于纤维在流动方向的取向，使流动方向上及与之垂直方向上的热膨胀系数产生很大的差异。 null影响成型速度制备导热或隔热性制品 复合材料的成型工艺几乎都伴随着加热和冷却过程。如果提高混合物的导热系数，可缩短加热或冷却时间，也就是提高成型速度。 复合材料可用作隔热或导热材料。以空气为填料的泡沫材料是良好的隔热材料，而以碳纤维、金属粉等为填料的复合材料则可作为导热性复合材料使用。null复合材料的导热系数在理想情况下可由下列复合规则估算： Pf——增强相的最大体积分数 实际的复合材料由于填料的形态等因素的影响，其导热系数各异。Nielsen考虑了这些因素后提出下列公式：A＝KE－1KE——爱因斯坦系数null各种材料的导热系数 填料的导热系数一般比聚合物的大，可预计，复合塑料的导热系数要比单纯聚合物的大。 null复合材料在一定温度下的比热基本上可由复合规则估算：使单位物量的某种物质升高单位温度所需的热量质量比热容量比热摩尔比热null 增强体的质量比热一般比基体稍小，因此复合材料的质量比热也比基体材料稍小。但两者的容量比热则无大差异。设各元素在处于液体和固体时的摩尔比热：null以碳酸钙为例，其比热可计算如下： Ca C O3(固体) 6.2＋1.8＋3×4.0＝20 碳酸钙的分子质量＝40.08 + 12.0l + 3×16＝100.09 故其质量比热cf＝20／100.09＝0.20cal／g＝8.38J／g 这个值与碳酸钙在20℃时的实测值为8.57J／g基本吻合。 null 一般表现为随增强体加入，玻璃化温度升高，玻璃化温度的升高程度与增强体加入量成正比。4.2.2 thermal resistance表征非结晶性聚合物耐热性的物理量是玻璃化温度Tg，结晶性聚合物是熔点Tm。聚合基复合材料的Tg与填充物含量的关系null基体聚合物的耐热性和FRTP的热变形温度 材料在1.86MPa或0.46MPa的受压负荷下，材料变形达一定尺寸时的温度。经填料填充后热变形温度明显上升经填料填充后热变形温度上升不大null热变形温度的负荷依赖性 null 聚合物的燃烧过程由两个相继的化学过程—分解和燃烧所组成，两者通过着火和热反馈相互联系。4.3 Combstion characteristics4.3.1 Combstion characteristics of polymers聚合物热分解热散失不燃物可燃物焦熔融物燃烧气体烟碳粒-Q1+Q2+Q2热散失热反馈null 以氧指数作为聚合物阻燃性的判据是Fenimore和Martin于1966年引入的。它是指聚合物着火后刚够维持燃烧时氧气在试验气体(氧、氮混合气体)中的最小百分含量。试验用 标准 excel标准偏差excel标准偏差函数exl标准差函数国标检验抽样标准表免费下载红头文件格式标准下载 试样在标准条件25℃和气流线速度为(4土1)cm／s下进行。 null一些聚合物的氧指数null4.3.2 Combstion characteristics of composite materials 三氧化二锑 三氧化二锑(Sb2O3)是最常用的阻燃填料之一，它是很多家电部件的难燃塑料基本配方的核心。三氧化二锑在单独使用时几乎没有阻燃效果，但与有机卤化物并用时却具有明显的阻燃效果。 钼化物 三氧化钼和钼酸锑等钼化物通常被用作PVC和含卤聚酯等塑料的阻燃剂。钼化物的阻燃效果虽略低于三氧化二锑，但它具有抑制燃烧时发烟的特点。无论钼化物单独使用，或与Sb2O3或与氢氧化铝并用都能发挥出优异的阻燃效果和明显的抑制发烟效果。 null 含磷化合物 用作聚合物阻燃添加剂的含磷化合物是多种多样的，例如，红磷、多磷酸铵、有机磷酸酯和亚磷酸酪、含磷聚合物等等。它们的阻燃机理不尽相同，取决于含磷阻燃剂的类别和被阻燃对象的类别。 氢氧化铝 对大多数热塑性和热固性聚合物，氢氧化铝是最常用的阻燃性填料之一。 除氢氧化铝外，凡在受热时可产生大量的水和二氧化碳气体的无机填料都具有一定的阻燃作用，例如，氢氧化镁、碱性碳酸镁(3MgCO3·Mg(OH)2·3H2O)、碱式碳酸钠铝(Na2O·A12O3·2CO2.2H20)和硼酸锌(2ZnO·2B203·3.5H2O)等。 null4.4 Photics characteristics 金属和陶瓷基复合材料都不透光,而透明玻璃钢具有透过紫外线的能力。 玻璃钢属于光学上非均一物体，当可见光通过玻璃钢时便产生散射现象。由于玻璃纤维的直径(6～10um)要比可见光的波长(0.4-0.76um)大好几倍，且相邻两根纤维之间的距离一般都不超过纤维直径的2倍，因此，需要用多次散射理论来描述光通过玻璃钢介质时的现象。 null根据多次散射理论，一束平行光经过厚度为h的散射层后，其透过部分T(透光率)可用 其中 式中 P——吸收系数； S——反射系数。 null对于玻璃钢，可取： 式中 nf——玻璃纤维的折射指数； nm——粘结剂的折射指数； Kf——玻璃纤维的吸收系数； Km——粘结剂的吸收系数； Vf——玻璃纤维的体积含量； d——玻璃纤维的直径。 null4.5 Corrosion resistance 复合材料应在100℃以下的介质侵蚀下，使用寿命达5年以上，即对大多数酸、碱、盐等化学介质稳定。 耐腐蚀复合材料 设计 领导形象设计圆作业设计ao工艺污水处理厂设计附属工程施工组织设计清扫机器人结构设计 主要应考虑以下三个问题：材料是否经得起介质的长期侵蚀?材料在受力情况下是否加速腐蚀? 材料组元间的腐蚀匹配等。Chapter 4 interface of composite materialsChapter 4 interface of composite materials Interface of composite materialsInterface of composite materialsCompatibility between matrix and fiber Physical compatibility Δα , σ’ Chemical compatibility reaction. stabilityChemical compatbility between fiber and matrixChemical compatbility between fiber and matrixPhase figure of aluminum based composite materials Al-C figure Solubility of C in AlAl-C figureAl-C figureCompounds of C and Al Al2C3 (~40%C) high temperature phase Al2C2 (~30%C) high temperature phase Al4C3 (~25%C) room temperature phase Reaction of C and Al 2050℃, C + L(7.4%C) → Al2C3 1850℃, Al2C3 + L(1.7%C) → Al2C2 1700℃, Al2C2 →C + Al4C3Al-B figureAl-B figureSolubility of B in Al Compounds of B and Al AlB2 (~975℃) AlB10 (1660~1850℃) AlB12 (~2070℃) Al-B figureAl-B figureReaction of B and Al 2070℃, L + B → AlB12 1850℃, L + AlB12 → AlB10 1660℃, AlB10 → L + AlB12 975℃, L + AlB12 → AlB2 660℃, L → α + AlB2 Al-SiC figureAl-SiC figureAl-Si-C (1) C + Si = SiC ΔG=-60.35KJ/mol (2) 4Al + 3C = Al4C3 ΔG=-196KJ/mol (2)-3×(1): 4Al + 3SiC = Al4C3 + 3Si ΔG=-196 + 3×60.35 = -14.95 620~660℃, SiAl-Fe figureAl-Fe figureSolubility of Fe in Al Compounds of B and Al Fe2Al (~81%Fe) Wetting of matrix on fiberWetting of matrix on fiberFundamental conception of wetting Wetting angle (θ) Adhesive work (W) Fanning pressure (π) Improvement methods of wetting Surface treatment of fiber Change composition of matrix High temperature and pressureTheory on wetting of composite materialsTheory on wetting of composite materials1) surface tension model interface tension model 2) free energy of interface reaction 3) wetting of metal-based composite materialsPhysic-chemical properties of interface Physic-chemical properties of interface Classification of composite material interface Mechanical bonding (physical) Dissolution bonding (chemical) Reaction bonding (chemical)Mechanical bondingMechanical bondingHB = F/A ， HB = 0.01E = 3σs ∵ f = τA = τyF/HB， f = βF ∴β= τy/HB ∵τy =σs/2， HB = 3σs ∴β= 1/6 =0.167 (0.1~0.6) σ= （T2-T1）（σm-αf）EmEf/（Em+Ef）Dissolution-separate out bondingDissolution-separate out bondingNiesz, if d1＜d2, that d1↓、d2↑ σ=-2γ/ρ Cr = C∞exp(3σM/ρRTr)Interface reaction bondingInterface reaction bondingS.S. Fick second law C = C∞-C0erf[x/(2Dt)1/2] δ2 = 2ΔCDt/C = KDt ΔC/C↓Interface reaction bondingInterface reaction bondingCompound Reaction diffusion δlim = Mechanical properties of interfaceMechanical properties of interfaceLongitudinal mechanical environment of interface (Ebert-Gadd model) σr = （υm-υf）Emε Transverse mechanical environment of interface (Adams figure) Mechanical properties of interfaceMechanical properties of interfaceRemanent stress of interface Heat stress Deformation stress Phase transformation stress Cf/Al, Em=54MPa, Ef=540MPa. 1173K, ?Theory of interface bondingTheory of interface bondingStrength bonding theory on interface Poor bonding theory on interface Pulling out theory Reaction belt theory Suface destruction theory Black box theoryFracture of composite materialFracture of composite materialFracture characteristics εm＜εf,τi↓ fiber pull out εm＜εf,τi↑ fiber fracture εm＞εf,τi↓ pull out and fracture Fiber and interface affect fracture of composite materialFracture of composite materialFracture of composite materialFracture toughness G = Gf + Gm Gf = σfεfLfVf/2 Gm = Gm0nullChapter 5 production of composite materialsChapter 5 production of composite materialsSurface treatment of fiber θ↓, bonding↑, stability↑ Clean surface & Form layer Physical treatment Washing & heating, HNO3 17%, N2 100%chemical treatmentchemical treatmentOxidation resistance coating Electrolyse coating Chemical coating Plasma coating PVD CVDMain processes to produce composite materials Main processes to produce composite materials Liquid phase processes Pressing casting Pressing impregnation Spraying deposition Slip casting Hot spray Reaction composite … Main processes to produce composite materialsMain processes to produce composite materials Solid phase prosses Powder metallurgy Film hot pressing Hot iostatic pressing Rolling Extrusion Explosion forming PVD …Metal matrix composite materialsMetal matrix composite materialsMain matrix: Al, Cu, Ti, Mg 纤维束-浸渍-丝带板-扩散粘结-复合- 纤维束-预成型-浸渍-挤压铸造-复合- Metal matrix composite materialsMetal matrix composite materials主要工艺：CVI， PLI（PIP），HP brittleness↑, E↑ 强化：晶界钉扎、位错网强化、缺陷尺寸减小、裂纹愈合等 韧化：裂纹偏转、内晶型次界面作用、内应力增韧、相变增韧、拔出效应等。Cement matrix composite materialsCement matrix composite materialsGlass fiber/cement Steel fiber/cement Particle/cementTesting of composite materialTesting of composite materialMechanical properties E, σ, τ… Microstructure OM, SEM, TEM… Physical properties L/d, θ，ρ，λ，α…Apllication Apllication Comparison of Mechanical PropertiesComparison of Mechanical PropertiesStrength at Higher Temperature Strength at Higher Temperature Fatigue S-N CurveFatigue S-N CurveFracture ToughnessFracture ToughnessMaterial Selection – Tensile LoadingMaterial Selection – Tensile LoadingMinimize w (weight)with since Thus, Material Selection – Buckling LoadMaterial Selection – Buckling LoadMinimize w with since Thus, Material Selection – Bending LoadMaterial Selection – Bending LoadMinimize w (weight)with (unit width) Thus, since Ashby’s DiagramAshby’s DiagramPassenger CarPassenger CarnullnullThe World’s Fastest BikeThe World’s Fastest BikeAll-Composite Business JetAll-Composite Business JetCommercial AirplaneCommercial AirplaneCommercial AirplaneCommercial AirplanenullMilitary AircraftMilitary AircraftnullF-15 Eagle FighterF-15 Eagle FighterMilitary HelicopterMilitary HelicopterThe first jet plane to fly around the globe with refueling The first jet plane to fly around the globe with refueling The Virgin Atlantic GlobalFlyer traveled a total distance of 26,389.3 miles in 76 hours and 45 minutes nullLeft: The Voyager aircraft, which made a 25000 mile nonstop flight around the world without midair refueling. Right: High-strength, low-density structural members of the Voyager are constructed from a series of cross plies consisting of graphite fibers that are aligned and embedded within an epoxy matrix. (Photograph courtesy of Hercules Inc.)Space ShuttleSpace ShuttleVirgin Space Ship Virgin Space Ship SpaceShipOne cracked the barrier to manned commercial space flight in June by flying 98,547 meters, or about 99 kilometers (328,491 feet, or about 62 miles) above Earth, just a little more than 120 meters (400 feet) above the distance scientists widely consider to be the boundary of space. The flight lasted 90 minutes.National Aero Space Plane (NASP)National Aero Space Plane (NASP)"...a new Orient Express that could, by the end of the next decade, take off from Dulles Airport and accelerate up to twenty-five times the speed of sound, attaining low earth orbit or flying to Tokyo within two hours..." Ronald Reagan (Use of high-temperature composites)SatelliteSatelliteBulletproof ProductsBulletproof ProductsMilitary Kevlar® Helmets Ballistic ClothingOther ApplicationsOther Applications具Kevlar 短纖及 Ceramics 六角板狀結晶，可提升抗刺穿能力，減少刺破機會。 碳纖維自行車車架碳纖維自行車車架TCRAlliance是一部結合了FO碳纖及Aluxx鋁合金科技的自行車,不但保留了碳纖的輕量及吸震優點,而且同時擁有了絕佳的競速效能接近於全碳纖車的等級TCRAlliance絕對是碳纖入門車款的最佳選擇 車架│GIANT formulaOne & Compact Road TM 碳纖/ALUXX SL車架 前叉│GIANT 碳纖前叉 重量│9.5kg 複合材料自行車車架技術發展歷程複合材料自行車車架技術發展歷程碳纖維網球拍碳纖維網球拍表面膜 Surface Coat Carbon Hybrid Cloth 碳纖維編紗束 Carbon Roving 碳纖維布 Carbon Cloth 尿烷芯材 Urethane Core柿木、金屬和碳纖維球頭之擊球距離和準確度比較圖柿木、金屬和碳纖維球頭之擊球距離和準確度比較圖氣墊船(Hovercraft)氣墊船(Hovercraft)A U.S. Navy LCAC hovercraft attached to the Amphibious assault ship USS Kearsarge Vosper Thornycroft VT2 氣墊船風扇轉子氣墊船風扇轉子nullSpecific Strength vs. Specific Modulus for Fibers Specific Strength vs. Specific Modulus for Fibers Temperature Effect on StrengthTemperature Effect on StrengthTemperature Dependence of Fiber StrengthTemperature Dependence of Fiber Strength