功能梯度材料的制备及在圆筒容器中的力学行为研究进展

阐述了功能梯度材料的概念和产生背景,以及功能梯度材料的各种制备技术的原理和特点,回顾了近年来圆筒容器用功能梯度材料应力研究取得的成果,并展望了功能梯度材料的发展趋势。同时着重论述了功能梯度材料在圆筒容器中的应力、应变分析研究现状及应用背景。     

钨-钼梯度功能材料的显微结构

自从梯度功能材料(FGM)的概念提出以后,全世界范围内对这种先进材料各种不同的应用做了大量的研究工作.FGM也能应用到动态高压技术中.震动技术为高压和高拉伸速率下材料性能的试验特征提供了特殊的能力.     

功能梯度压电带中偏心裂纹对SH波的散射问题

功能梯度材料在机械、光电、核能、生物工程领域的应用非常广泛.但由于生产技术及工作环境等方面的原因,功能梯度材料内部常常产生各种形式的裂纹并最终导致材料破坏,这将会给材料所处的整个系统带来巨大损失.因此研究功能梯度材料的断裂问题对于该种材料的设计,制备和合理、安全的应用具有极大的促进作用.本文在压电材料线性宏观理论下,研究了功能梯度压电带中偏心裂纹对SH波的散射问题.借助于积分变换方法,在电非渗透型边界条件的情况下,将所考虑的问题转化为奇异积分方程,运用Gauss-Chebyshev数值积分方法对奇异积分方程进行了数值求解,进而得到了裂纹尖端的应力和电位移强度因子.     

Ti基功能梯度材料的研究进展

综述了Ti基功能梯度材料的各种制备方法、性能评价以及在航空机械和生物医药等方面的应用,展望了Ti基功能梯度材料的未来发展及前景。     

W-Cu功能梯度材料的研究现状

W-Cu功能梯度材料是一种新型非均质复合材料。介绍了W-Cu功能梯度材料的基本特征及用途,综述了W-Cu功能梯度材料的制备方法,并介绍了电沉积法在制备功能梯度材料中的应用情况,分析了其制备W-Cu功能梯度材料的可行性,最后提出了今后W-Cu功能梯度材料需要解决的问题。     

等离子熔射制备梯度功能材料技术

梯度功能材料是一种具有特殊结构和特点的新材料,对该材料的深入研究有助于提升和改造传统的材料产业.应用等离子熔射技术制作了梯度功能材料,对梯度成分进行了设计分析,同时测试了梯度涂层的金相组织以及显微硬度.结果表明梯度功能材料比传统的单一材料以及复层材料使用性能和寿命大大提高.功能梯度材料应用于现代制造业以及对材料表面进行改性将对我国工业技术的发展产生重大影响.     

功能梯度材料的制备、应用及发展趋势

功能梯度材料是一种新型材料,由于其结构和性能的优异特性,已成为材料领域研究的热点.对国内外功能梯度材料的研究进展进行了综述,重点阐述了功能梯度材料的制备、应用及其发展趋势.     

功能梯度材料及其在太阳能电池中的应用

功能梯度材料(Functionally Gradient Materials,FGM)由于其独特的性能及作为一种全新的概念已引起越来越多科学家的重视.本文简要回顾了功能梯度材料的研究发展史,对FGM的各种制备技术进行了总结,并对其在太阳能电池方面的应用进行了重点介绍.     

梯度功能材料的研究现状与展望

综述了国内外梯度功能材料(FGM)的研究现状,介绍了梯度功能材料的优化设计原则、制备工艺与特性评价,其中重点介绍了梯度功能材料制备工艺的基本原理和工艺方法,如粉末冶金法、气相沉积法、自蔓延高温合成法、热喷涂法、电沉积法、激光熔敷法等,分析了各种制备工艺技术存在的利弊,展望了梯度功能材料的发展前景与方向.     

功能梯度材料的研究现状及展望

功能梯度材料(FGMs)是一种全新的非匀质复合材料,因其优异的结构性能和潜在的应用价值受到人们的高度重视。简要阐述了功能梯度材料的发展历程、研究现状、应用,详细总结和分析了功能梯度材料的制备方法,最后展望了功能梯度材料的发展前景。     

新型功能梯度材料研究现状及发展方向

介绍了功能梯度材料的研究现状及发展方向,针对功能梯度材料研究的核心问题——材料合成技术,综述了低温制备工艺研究现状,最后对功能梯度材料进行了展望。     

Numerical analysis on near net shape forming of Al–Al3Ni functionally graded material

The results of numerical studies on the near-net shape forming of Al–Al₃Ni functionally graded material (FGM) are presented and are compared with the experiments. FGM billets at an elevated temperature of semi-solid condition are set in a container and are subject to backward extruding, and FGM cups are obtained. Due to the composition gradient of FGM the effective viscosity of semi-melt FGM billet varies spatially. The flow/deformation of semi-melt FGM billet is strongly influenced by the spatial variation of effective viscosity. Some characteristic behaviors of flow/deformation of FGM during the semi-solid process are presented and discussed.     

功能梯度材料

介绍了功能梯度材料的提出，开发流程，研究现状，对于当前功能梯度材料的设计过程，制备方法，性能评价方法和实验手段进行了详细叙述，提出了功能梯度材料应进一步发展的方向。     

Thermomechanical bending analysis of functionally graded sandwich plates with both functionally graded face sheets and functionally graded cores

The bending response of functionally graded material (FGM) sandwich plates subjected to thermomechanical loads is investigated using a four-variable refined plate theory. A new type of FGM sandwich plate, namely, both FGM face sheets and an FGM hard core, is considered. Containing only four unknown functions, the governing equations are deduced based on the principle of virtual work and then these equations are solved via the Navier approach. Analytical solutions are obtained to predict the deflections and stresses of simply supported FGM sandwich plates. Benchmark comparisons of the solutions obtained for a degradation model (functionally graded face sheets and homogeneous cores) with ones computed by several other theories are conducted to verify the accuracy and efficiency of the present approach. The influences of volume fraction distribution, geometrical parameters, and thermal load on dimensionless deflections and normal and shear stresses of the FGM sandwich plates are studied.     

梯度功能材料的研究

梯度功能材料是五年前由日本科学家提出的新概念和新思想,其两侧由不同性能的材料组成,以对付苛刻的使用环境;而中间部分的组成和结构又是连续变化的,使其内部界面消失,以减小和克服结合部位的性能不匹配因素。这类材料在航天事业和核工业中有看广阔的应用前景和极高的使用价值。本文着重介绍了梯度功能材料的设计思想、目前的研究现状、以及我们在这方面做的一些工作。并综述和比较了各类制备工艺技术。     

Experimental Investigations on Deformation and Fracture Behavior of Glass Sphere Filled Epoxy Functionally Graded Materials

In this paper, deformation and fracture behavior of glass sphere filled epoxy functionally graded materials (FGM) are numerically evaluated and experimentally studied. The fabrication of the FGM is described in detail, and the spatial gradation of elastic modulus and the microscopic structure in FGM are measured and analyzed. The deformation and fracture characterization of the FGM specimen with a crack oriented along the direction of the elastic gradient under three point bend are studied by the experimental and the finite element method. The influences of crack location at both the stiff and the compliant sides of the FGM specimen on crack initiation, deformation field and stress intensity factor are analyzed. The results are: (a) The neutral-axis in the FGM specimen under three-point-bending will shift toward the stiffer side; (b) The initial fracture load increases with the increase of elastic modulus at the crack tip; (c) The elastic gradients shield a crack on the compliant side and lower the stress intensity factor when compared to the one with crack on the stiff side. These results will be useful for better design and reliable evaluation of FGM.     

Effect of anisotropy on steady state creep in functionally graded cylinder

The steady state creep in transversely isotropic functionally graded cylinder, operating under internal and external pressures, has been investigated. The cylinder is composed of functionally graded material (FGM) containing silicon carbide whiskers in a matrix of 6061Al. The creep behavior of the FGM has been described by a threshold stress based creep law. The effect of anisotropy on creep stresses and creep rates in the FGM cylinder has been analysed and compared with an isotropic FGM cylinder. The anisotropy is represented by a parameter α, defined as the ratio of radial (or axial) and tangential yield strength. The study reveals that in an anisotropic FGM cylinder i.e. when α deviates from unity, radial and tangential stresses are marginally affected whereas axial and effective stresses are significantly affected as compared to those in an isotropic FGM cylinder. The strain rates as well as inhomogeneity in strain rates in the FGM cylinder decrease significantly when α reduces from 1.3 to 0.7. The magnitude of stresses, strain rates and inhomogenity in strain rates in the FGM cylinder, subjected to internal pressure alone, could be significantly reduced by subjecting it to both internal and external pressures though the stress inhomogenity in the FGM cylinder increases.     

非均匀热载荷作用下功能梯度梁的非线性静态响应

由于功能梯度材料结构沿厚度方向的非均匀材料特性,使得夹紧和简支条件的功能梯度梁有着相当不同的行为特征。该文给出了热载荷作用下,功能梯度梁非线性静态响应的精确解。基于非线性经典梁理论和物理中面的概念导出了功能梯度梁的非线性控制方程。将两个方程化简为一个四阶积分-微分方程。对于两端夹紧的功能梯度梁,其方程和相应的边界条件构成微分特征值问题;但对于两端简支的功能梯度梁,由于非齐次边界条件,将不会得到一个特征值问题。导致了夹紧与简支的功能梯度梁有着完全不同的行为特征。直接求解该积分-微分方程,得到了梁过屈曲和弯曲变形的闭合形式解。利用这个解可以分析梁的屈曲、过屈曲和非线性弯曲等非线性变形现象。最后,利用数值结果研究了材料梯度性质和热载荷对功能梯度梁非线性静态响应的影响。     

A meshfree radial point interpolation method for analysis of functionally graded material (FGM) plates

A meshfree model is presented for the static and dynamic analyses of functionally graded material (FGM) plates based on the radial point interpolation method (PIM). In the present method, the mid-plane of an FGM plate is represented by a set of distributed nodes while the material properties in its thickness direction are computed analytically to take into account their continuous variations from one surface to another. Several examples are successfully analyzed for static deflections, natural frequencies and dynamic responses of FGM plates with different volume fraction exponents and boundary conditions. The convergence rate and accuracy are studied and compared with the finite element method (FEM). The effects of the constituent fraction exponent on static deflection as well as natural frequency are also investigated in detail using different FGM models. Based on the current material gradient, it is found that as the volume fraction exponent increases, the mechanical characteristics of the FGM plate approach those of the pure metal plate blended in the FGM.     

面向等离子体SiC/C功能梯度材料的研究

用热压制备了SiC/C功能梯度材料（Functionally Graded Materials,FGM），评估了SiC/C FGM的微观组织和物理性能。其中SiC/C FGM的耐等离子体冲刷行为显示了它们在核聚变实验装置中作为面向等离子体材料的良好应用前景。