Papers by Keyword: Multifunctional Materials

Abstract: The aim of this study is to investigate passive control strategies using Phase Change Materials in Machine Tools (MTs) thermostabilization. By considering the main issues related to the thermal stability, authors presented the application of novel multifunctional materials to Machine Tools structures. A set of advanced materials are considered: aluminium foams, corrugate-core sandwich panels and polymeric concrete beds. The adopted solutions have been infiltrated by phase change materials (PCMs) in order to maintain the thermal stability of MTs when the environmental temperature is perturbed. The paper shows the results of simulative and experimental tests.

Abstract: In order to learn of pyrolytic behavior of wheat straw multifunctional materials, the extractives of wheat straw biomass were adsorbed and determined by Py-GC-MS. And the main constituents were stigmasterol, vitamin e, campesterol, .gamma.-sitosterol, stigmasterol, 22,23- dihydro-, nonacosane, stigmastan-3,5,22-trien, heneicosane, lup-20(29)-en-3-one, 1,2- benzenedicarboxylic acid, buty l 2-methylpropyl ester, stigmast-4-en-3-one, stigmastan-3,5-diene, 4,22-stigmastadiene-3-one, cholest-5-en-3-ol (3.beta.)- , pyridine-3-carboxamide, oxime, etc.

Abstract: In order to learn of pyrolytic behavior of bagasse multifunctional materials, the extractives of bagasse biomass were adsorbed and determined by Py-GC-MS. And the main constituents were 1-phenanthrenecarboxylic acid,1,2,3,4,4a,9,10,10a-octahydro-1,4a-di methyl-7-(1-methylethyl)-( 37.99%), decanoic acid, 1,2,3-propanetriyl ester(5.73%), tridecane, 2-methyl-(5.09%), dodecanoic acid, 1-(hydroxymethyl) -1,2-ethanediyl ester(4.52%), stigmastan-3,5-diene(3.81%), glycine, furan-2-yl-methyl ester(3.45%), 1-hexacosene(2.18%), 1-docosene(2.08%), kaura-9(11),16-dien-18-oic acid, (4.alpha.)- (2.07%), etc.

Abstract: Technical importance of multi-ferroic approach for designing advanced multi-functional actuator/sensors based on a mutual coupling effect between ferroic material elements is pointed out for intelligent/smart technology. Two types of multi-ferroic actuator/sensor devices. i.e. (1) magnetically driven composite actuator and (2) multi-functional surface acoustic wave (SAW) sensor by MEMS are presented. First, a large-scale robust composite actuator is the composite structure which is reinforced by the superelastic fiber or lamellar of shape memory alloys (TiNi) in the ferromagnetic metal (Ni) matrix. This multi-ferroic composite can be driven with high speed as well as considerably enhanced strain by applying a wireless magnetic field. Secondarily, multi-functionally designed, multi-ferroic senor device using surface acoustic wave (SAW) is introduced. On the surface part between IDTs, environmentally active material films such as SMA, FSMA, magnetostrictive alloy etc. are formed by magnetron-sputtering. Various environmental sensing parameters i.e. temperature, magnetic field strength, stress, loading hysteresis and internal damage etc. can be evaluated nondestructively from the signal analysis of amplitude and phase change of SAW. Consequently, these results show the promising new types of multi-functional composite actuator and sensor based on multi-ferroic effect.

Abstract: A new designing concept to realize multifunctional structural material systems is proposed and demonstrated in this paper. The concept can be explained as follow: There exist a couple of competitive structural materials which normally compete with each other because of their similar and high mechanical properties, and they tend to have secondary properties which are different from each other or opposite among them. So if they are combined together to make a composite, the similar properties, normally high mechanical property, can be maintained, and the other dissimilar properties conflict with each other, which will generate functional properties. According to the proposed concept, a CFRP (carbon fiber reinforced plastics)/aluminum laminate was fabricated and its actuation capabilities and multifunctionality were successfully demonstrated. A titanium fiber/aluminum matrix composite was also fabricated, where the fiber was oxidized for electrical insulation and strengthening. This material system is very simple, but it can generate many useful functions such as heating, actuation, temperature sensing, deformation sensing and healing.

Abstract: The aim of the paper is to present the influence of a new multifunctional material, a master alloy named Al-Sr-Ti-B, in aluminum foundry alloys. The Al-Sr-Ti-B master alloy represents a new combination of two master alloys, already known in aluminum industry, AlTiB and AlSr, used in treatment of aluminum alloys for grain refining and modification. As Strobloy, our master alloy contain fast dissolving SrAl4 particles and also nucleating particles as TiB2 and (Al,Ti)B2 which are important first in modification and second in grain refining of aluminum alloys. The paper presents optic and electron microscopy studies realized on AlSi7Mg alloy treated with this new multifunctional material

Abstract: Multifunctional materials are created by intimately integrating different materials. The assessment of the local properties and composition of the different components of such a multifunctional material necessarily relies on techniques with sufficient spatial resolution. The increased use of these microanalysis or microprobe techniques has created a demand for appropriate quality assurance tools, such as reference materials. In this paper a number of issues related to the certification of reference materials for multifunctional materials are discussed. Examples of reference materials are shown to illustrate the particular challenges the reference material producer is faced with such as micro-homogeneity, minimum sample intake and stability.