Showing papers on "Functionally graded material published in 1993"

The Stresses and Strains in a Thick-Walled Tube for Functionally Graded Material under Uniform Thermal Loading

Abstract: The combination of materials consists of aluminium and silicon carbide particles, and the distribution profiles are assumed to be the same as the expression for the plaster/corundum model FGM material

A magnetic-functionally graded material manufactured with deformation-induced martensitic transformation

Abstract: Functionally graded materials (FGMs) are some of the most promising materials, whose compositions and microstructures are varied continuously from place to place [1-3]. FGMs have been developed to decrease the thermal stress induced by the large temperature difference within the thickness of thermal barrier materials. FGMs are applicable not only to the mechanical field, but also to the electronic, chemical, optical, nuclear, biomedical and other fields [1, 2]. For instance, a magnetic sensor for position measurement may be developed if the magnetic property of the material used for the sensor is varied continuously from place to place. However, most of the previous studies on FGMs have dealt with the mechanical function, and little attention has been focused on other functions and their applications. FGMs can be classified into composite and monolithic materials. Although most of the current FGMs are made of composite materials, they are not considered to be preferable from the viewpoint of material recycling, because it is difficult to separate the dispersion phases from the composite matrices. In contrast, monolithic FGMs have the possibilities of being recycled or the recovery of their functions using very easy methods such as melting or other heat treatments. In particular, metallic FGMs are considered to be readily obtainable, since various conditions of plastic work and heat treatment result in different microstructures depending on the conditions. Unfortunately, however, very few works have been concerned with monolithic FGMs. It is known that the paramagnetic phase in austenitic stainless steels, such as an Fe-18Cr-8Ni, transforms into ferromagnetic o:'-martensite phase when they are plastically deformed in a particular low-temperature region [4, 5]. The amount of deformation-induced martensite increases at a larger strain and at a lower deformation temperature. Thus, the saturation magnetization of the deformed austenitic stainless steel increases with increasing strain at a constant deformation temperature. Therefore, gradually inhomogeneous deformation is considered to bring about the change of the saturation magnetization depending on the local strain. If the relationship between the amount of deformation-induced martensite and the amount of plastic