先进复合材料工艺理论基础-界面.ppt

1、先进复合材料工艺理论基础第三讲：界面反应,主讲人：于家康 Tel：88494987(O）88486066（Lab)M) Email: ,提 纲,引言 金属-陶瓷界面反应 自生复合材料的界面反应,引 言,外加复合材料： 金属基：C+Al Al4C3 陶瓷基：C+Si SiC 碳基： 聚合物基：,引 言,自生复合材料： in situ metal matrix composites aluminum, titanium, copper, nickel and iron), and second-phase particles (including borides, car

2、bides, nitrides, oxides and their mixtures,金属-陶瓷界面反应,铝与陶瓷： 3SiO2+4Al2Al2O3+3Si,金属-陶瓷界面反应,钛与陶瓷： 5Ti+B4C4TiB+TiC,自生复合材料的界面反应,自生工艺中的反应 自生反应热力学 自生陶瓷相的形成机理 自生复合材料的显微组织,自生工艺中的反应 固-液反应自蔓延高温合成（SHS),Composition of reactant powder mixture, measured maximum temperatures, and average propagation rates,自生工艺中的反应

3、固-液反应放热弥散（XD),自生工艺中的反应 固-液反应反应热压（RHP),3TiO2+4Al+6B2Al2O3+3TiB2 Molecular ratio of in starting TiO2AlB materials and nominal content of generated phases (vol.%) in composite products,自生工艺中的反应 固-液反应燃烧辅助铸造,5Ti+B4C4TiB+TiC a stoichiometric amount of reactant powders is first blended thoroughly and then

4、compacted into pellets. The compacted pellet and the required amount of matrix are melted and then cast into a graphite mold. The ceramic reinforcements are formed in situ during melting via exothermic reactions between the reactants,自生工艺中的反应 固-液反应直接反应合成（DRS),Ticu+CTiC Ticu+B2O3+3CTiB2+3CO compacts

5、of reactant powders, are directly added into molten metal and the ceramic reinforcing particles are formed in situ through the exothermic reaction between reactants or between reactant and some component of the melt,自生工艺中的反应 固-液反应熔剂辅助合成（FAS),3K2TiF6+13Al3TiAl3+3KAlF4+K3AlF6 2KBF4+3AlAlB2+2KAlF4 AlB2

6、+TiAl3TiB2+4Al During the synthesis, mixed salts of potassium hexafluorotitanate (K2TiF6) and potassium tetrafluororate (KBF4) are introduced into a stirred aluminum melt with an atomic ratio in accordance with Ti/2B,自生工艺中的反应 固-液反应熔剂辅助合成（FAS),自生工艺中的反应 固-液反应反应自发浸渗（RSI),3SiO2+4Al2Al2O3+3Si SiO2 partic

7、ulate preform placed inside a quartz tube of 9mm diameter and 15mm length is immersed in the Al melt Al matrix composites reinforced with micro Al2O3/Al particles via reactive infiltration of molten Al into preforms of SiO2 or Mg+SiO2 mixtures at 1348K,自生工艺中的反应 固-液反应其它,金属直接氧化(DIMOX) 快速凝固技术(RSP) 反应挤压

8、铸造(RSC),自生工艺中的反应 气-液-固反应(VLS),2Ti+N22TiN Al4.5Mg6.2Ti (in wt.%) parent alloy was melted in an induction furnace, and subsequently, the chamber was back-filled with purified argon. Upon reaching an appropriate processing temperature, clean N2 gas was introduced into the Al alloy melt,自生工艺中的反应 固-固反应机械

9、合金化(MA),Mechanical alloying (MA) is a solid state powder processing method which involves repeated cold drawing and fracture of particles as a result of the high energy ballsample collisions. This method can be used to produce fine-grained alloyed powder particles in metalmetal and metalceramic syst

10、ems,自生工艺中的反应 固-固反应反应热压(RHP),Nominal content of generated phases (vol.%) in in situ Ti-based composites by assuming in situ reactions take place completely in all systems,自生工艺中的反应 液-液反应,The process involves the reaction between two metal streams to form refractory particles. Two or more high-speed, t

11、urbulent, molten-metal streams containing components of a high- temperature (ceramic) phase, for example CuTi and CuB, are made to impinge upon one another in a mixing chamber, resulting in intimate mixing and reaction to produce the second phase. The resulting mixture can then be cast in a mold or

12、rapidly solidified via melt spinning or atomization. This technology is effective in producing copper matrix composites reinforced with nanoscale TiB2 particulates (50nm) for the electrical applications,自生反应热力学 AlTiC system,Change of Gibbs free energy G as a temperature for TiC, Al4C3 and Al3Ti form

13、ation,自生反应热力学 AlTiC system,Thermodynamic data as a function of temperature for the reaction 3Al3Ti(s)+Al4C3(s)3TiC(s)+13Al(l),自生反应热力学 AlTiC system,Thermodynamic data as a function of temperature for the reaction 3Al3Ti(s)+C(s)TiC(s)+3Al(l),自生反应热力学 AlTiB system,Al+2BAlB2 3Al+TiAl3Ti Al3Ti+2BTiB2+3Al

14、Ti+2BTiB2,自生反应热力学 TiB4C system,Change of Gibbs free energy G as a temperature for the reactions 5Ti+B4C4TiB+TiC and 3Ti+B4C2TiB2+TiC, respectively,5Ti+B4C4TiB+TiC,3Ti+B4C2TiB2+TiC,自生反应热力学 TiTiB2 system,Change of Gibbs free energy G and formation enthalpy H as a temperature for the reaction TiB2+Ti2T

15、iB,自生陶瓷相的形成机理,固溶-析出 Al-Ti-C Al-Ti-B Al-C Al-B4C,自生陶瓷相的形成机理,固-液界面反应 For a powder mixture of TiN and B TiN+2B+AlTiB2+AlN For the powder mixture of Ti and B4C, Al3Ti is formed first, followed by a reaction between Al3Ti and B4C,3Al3Ti+B4C2TiB2+TiC+9Al,自生陶瓷相的形成机理,熔体中固-固反应 Ti2O3(s)+2AlB2(s)2TiB2(s)+ -Al2O3(s) 3TiO2(s)+3AlB2(s)+Al(l)3TiB2(s)+2 -Al2O3(s),自生复合材料的显微组织,Optical micrograph showing uniform dis