The proposal
Acoustic controls the physical-mechanical properties of composites
Various heterogeneous materials (composites) are widely applied in technique. They include, for example, products of concrete, cast iron, powder metallurgy products (hard alloys WC-Co, mixed nuclear fuel, W-Cu composite materials, etc.), bodies of live beings with fine dispersed solid inclusions, porous rocks in the Earth bowels impregnated with liquids etc. All physical-mechanical properties of composites significantly depend both on their phase composition and their separate components properties. The development of composites technology, high-quality requirements to composite properties, optimum conditions for the operation and composites properties stability check demand to develop a nondestructive mass express check of phase composition of composites (as one of the most important quality) since existing phase composition analysis methods (for example, x-ray) can not do it. High measurements accuracy, self-descriptiveness and sensitivity of acoustic characterization of solids - resonant frequency of oscillations or their attenuation, ultrasonic waves velocity etc. - are widely known and can be useful for evaluation of point, line and naturally 3-d inclusions (as in various composites). These dignities of acoustic methods are already widely used in science and technique for various materials monitoring and study. In addition, extensive experimental and theoretical data, that are now available, define a choice of ultrasonic parameters for sounding as they have biunique conformity with various physical-mechanical properties of composites and technical possibility for monitoring materials. Guided by the stated, the authors of the proposal during the past 20 years have developed and experimented with a number of methods and devices for the study and checking various single materials and composites in a wide temperature range up to 2000°C and frequency range (0.01 ... 10МГц), using resonant oscillations and sound impulse . The results of research and checking are reflected in the number of patents, articles and in computer program ACP-MPC [1-3]. ACP-MPC program (acoustic checking of physical-mechanical properties of composites) intended for implementation of express-evaluation of a number of physical-mechanical properties macroisotropic homogeneous composites. The program can be used to evaluate: -porosity of powder sintered materials;
- composition of two-phase compact (100% density) composite for products which have constant composition during the technological process or products which change composition of one of the components in the technological process; -composition and porosity of three-phase composite constituting a porous homogeneous mixture of the two components; - in case of impossibility to manufacture compact sample material (as constituent of composite) and measuring it true speed of sound and density a new method was designed to their evaluation using two porous samples; - all elasticity modules. In addition, porosity or 2-phase composite evaluation correctness methods where developed. This methods are based on use of standards, randomly selected from controlled batch of products and characterize on the porosity or composition of any known or proposed ways. The program provides parameters evaluation by using the wave-particle approaching and measured densities and sound speeds of identical types of oscillations in products or samples of each component, which were controlled by resonant or pulse way in same physical conditions. The program was tested in dozens of different macroisotropic (yet!) composites, presented in technical literature. There are hard alloys WC-Co, porous composite materials SiC-Si, Si3N4-Si, SiC-Al2O3, TiC-Al2O3, W-vinyl, W-Cu, sintered glass spheres-H2O and many others. Here are examples of calculations on the program ACP-MPC. 1. Set of characteristics of sintered WC-Co, necessary for calculations, adopted from works L. Frohlich, H. Hoffman (1972)- Wissenschaftliche Zeitschrift der Technichen Hochschule Otto von Guericke Magdeburg 16, , 1 Heft s. 11-22, Ф.Ф. Воронов, Д.Б. Балашов -ФММ, 18 (1960), no. 4, 616-20. Use longitudinal waves and densities of carbide and composite leads to the following results:
Measured: -sound speed in WC and composite ВК-6: 7175 m/s and 6920 m/s -WC and ВК-6 density: 15.65 g/cm3 and 14.99 g/cm3
Calculated: -volume Co cohesive: C = 9.97vol% or 6.0mass%. -longitudinal sound speed in Co: VlCo= 4970 m/s -longitudinal elasticity module: L = 22747kg/mm2 -Co cohesive density: ρCo= 9.03 g/cm3
A similar shear waves and densities use gives:
Measured: - sound speed in WC and composite ВК-6: 4335 m/s and 4144 m/s - WC and ВК-6 density: 15.65 g/cm3 and 14.99 g/cm3
Calculated: -volume Co cohesive: C = 9.97vol% or 6.0mass%. -shear sound speed in WC: VsCo = 3004 m/s -Co density: ρCo= 9.03 g/cm3 -shear module: G = 8309кг/mm2 -Poisson’s ratio: ν = 0.212 -Young’s modulus: ECo = 20146кг/mm2 -bulk elasticity modulus: BCo= 11688кг/mm2 -mass solution W in Co: Cw = 8.2mass%.
Check with these three methods (five methods exists) gives: 1) using mixtures rule: CCo = 9.97vol.%. 2) using longitudinal speeds: CCo = 9.966vol.% 3) using shear speeds: CCo = 9.96vol.%. Received characteristics for Co-binder, combined with data for composite ВК-6 can be used to establish correlation with hardness, fracture toughness, etc. These data for Co-binder and composite with the possibility of self-checking have been received for the first time.
2.T.Y. Plona (Appl. Phys. Lett. 36 (4) Febr. 1980, p.259-61) penetrated porous frame of sintered glass spheres with water and received a glass-water composite with varying concentrations of H2O. In assumption of composite compactness (i.e. porosity p= 0) the program can calculate the composition of a 2-phase composite using longitudinal oscillations and as a standard, for example, composite № 1 using theoretical values (mixtures rule) composites densities and minimizing porosity values (p> 0.1%) the program can evaluate the composition of composites by the 3-phase composite computation scheme.
1)Measured: - glass sound speed : 5690 m/s - water sound speed: 1460 m/s - composite № 1 sound speed : 4050 m/s Calculated: - CH2O =28. 46 (Plona CH2O = 28.3%)
Measured: - glass sound speed : 5690 m/s - water sound speed: 1460 m/s - composite № 2 sound speed : 4180 m/s
Calculated: - СH2O=25.8 (PlonaCH2O=25.8%)
2)Let’s assume composite № 1 is a standard with vol.%H2O = 28.3%. Then calculations for composite № 2 leads to:
Measured: - glass sound speed: 5690 m/s - composite № 2 sound speed: 4180 m/s -standard sound speed: 4050 m/s
Calculated: - CH2O = 25.71 ( Plona CH2O= 25.8% )
1) Calculations for 3-phase composite using theoretical density of a composite:
a) Measured: -glass density : 2.48 g/cm3 glass sound speed: 5690 m/s -water: 1.0 g/cm3 water: 1460 m/s -composite № 1: 2.06 g/cm3 composite: 4050 m/s
Calculated: -p=0.1% -CH2O = 28.2vol.% (Plona CH2O= 28.3%)
b) Measured: -glass density : 2.48 g/cm3 glass sound speed: 5690 m/s -water: 1.0 g/cm3 water: 1460 m/s -composite № 2: 2.098 g/cm3 composite: 4180 m/s
Calculated: -p=0.1% -CH2O = 25.6vol.% (Plona CH2O= 25.8%)
30 (1995) 834-6). Authors give all necessary data to use ACP-MPC. Composition and porosity we can calculate by multiple ways.
1) While p = 0 we can calculate the volumetric part of Al2O3 (same as authors) only with using the sound speeds:
a) Measured: - longitudinal sound speed in SiC: 11461 m/s -in Al2O3: 10059 m/s -in composite: 10454 m/s
Calculated: -C Al2O3=70.6 vol. %.
b) Measured: -shear sound speed in SiC: 7459 m/s -in Al2O3 : 6399 3 m/s -in composite: 6689 m/s
Calculated: - CAl2O3 = 71.1об%.
2) Porosity exists, and we make calculations for 3-phase composite: a) longitudinal waves - density of SiCW: 3.181 g/cm3 sound speed in SiC: 11461 m/s -Al2O3: 3.986 g/cm3 Al2O3: 10059 m/s -composite: 3.73 g/cm3 composite: 10454 m/s
-p = 0.12% -CAl2O3 = 68.7%
b) shear waves -the density of SiCW: 3.181 g/cm3 sound speed in SiC: 7493 m/s - Al2O3: 3.986 g/cm3 Al2O3: 6399 m/s -composite: 3.73 g/cm3 composite: 6689 m/s
-p = 0.22% - СAl2O3=69.2%
3) Using only densities and the rule of mixtures we have CAl2O3 = 68.2vol.%. The authors of the article gives CAl2O3= 69.2 .... 71.4vol.%, evaluated them by different ways.
Thus, as follows from the presented examples, program ACP-MPC has opportunities for research and checking different types of composites, development the best technological regimes for their manufacture, subsequent evaluation their suitability for further exploitation.
In summary we will note, that knowledge of composition and porosity of composites permit their physical-mechanical properties evaluation, applying existing models and excluding labour-intensive research of empirical dependencies. Developed method and program ACP-MPC can be applied everywhere, where new composite materials are developed and operated.
References.
в диапазоне температур 20-2000°С в Кн. «Карбиды и сплавы на их основе», «Наукова Думка», Киев, 1976, с.104-7 В.И. Князев, В.Г. Букатов, О.С. Коростин. 2. В.И. Князев, В.Г. Букатов, Д.Р. Кутырев Изобретение № 1817017G01N29/00 от 23.05.93 БН №19 Способ акустического определения физических характеристик спекаемого материала. 3. Программа для ЭВМ «Акустический контроль физико-механических свойств композитов» В.И. Князев № 2008615672 от 27.11.2008
Senior researcher , Ph.d. _ _ _ _ _ _ _ _ _ _ _ Mr. Knyazev
e-mail для связи : osa_57@mail.ru
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