Ukrainian Views on Applying Advanced Materials F.H. Froes

INTRODUCTION

Held during October 1992 in Kiev, Ukraine, the conference New Materials and Their Application in Engineering Industries was coordinated by the I.N. Frantsevich Institute for Problems of Material Science, Academy of Sciences of Ukraine, on behalf of the Ukrainian government and under the auspices of the Working Party on Engineering In­dustries and Automation, United Na­tions Economic Commission for Europe. The purpose of the conference was to provide a forum for exchanging infor­mation and experience on methods and technologies for the production and en­gineering application of new materials. Product quality, reliability, and increased productivity were emphasized over theoretical aspects.

The conference was chaired by V.

AIRCRAFT DESIGN

The largest aircraft in the world, the AN-225 transport, was designed at the Antonov Design Bureau and is produced in Ukraine. It was, therefore, of great interest to hear the observations of the bureau's director, P.V. Balabuev, who presented "New Concepts for the Manufacture of Load Bearing Structures from Polymer CompOSites for Aircraft: Design, Manufacture, and Certification."

Balabuev reported that large aircraft being built in Ukraine are constructed of 30 percent polymeric composites. He projected that by the year 2000, this fig­ure could reach as high as 50 percent for greater weight savings. Affected com­ponents include wings, where (com­pared to aluminum) composites can lead to a 20 percent decrease in surface area, resulting in fuel savings of 20-30 per-

COLLOIDAL CHEMISTRY SYNTHESIS

In an interesting presentation, V.V. Goncharuk of Ukraine emphasized that unique properties could be incorporated into materials through a deep funda­mental knowledge of how materials are being produced or synthesized. To il­lustrate such a concept, he noted that a dispersion of second-phase particles in a matrix could be produced either by dispersing the particles directly in the matrix or by separately preparing the dispersoids and then implanting them into the matrix.

Regarding work done to date, the author noted that a colloidal chemistry approach could be used to produce metallopolymeric materials (using Cu, Ag, Pd, or Au) with superconducting characteristics. He also reported on the

Trefilov, director of the LN. Frant­sevich Institute. E. Seitz of Ger­many and F.H. Froes of the United States were the vice chairs. In ad­dition to the formal conference, there were also opportunities for attendees to visit local universi­ties, research institutes, and pro­duction plants, underscoring Kiev's repu tation as a major center for the science and technology of advanced materials.

As the conference and subse­quent tours proved, much excel­lent science has been performed and many advanced materials are

The purpose of the conference was to provide a forum for exchanging information and experience on methods and technologies for the production and engineering application of new materials. Product quality, reliability, and increased productivity were emphasized over theoretical aspects. in various stages of commercial­

ization. However, the influx of outside money is necessary for progress to continue. As a result, many organizations in the region are eager to establish joint programs with Western countries.

development of silicon organic coatings capable of protecting metals from corrosion.

Goncharuk concluded the pre­sentation by noting developments in magnetic powder particles, ma­terials for medical applications, and the syntheSis of catalytic ma­terials for use in processing oil and cleaning contaminated water.

CERAMICS

In summary remarks, the con­ferencechair, V. Trefilov, described ceramics work being conducted in Ukraine, including work on devel­oping useable ceramics for very high-temperature applications and in electronic circuitry. He also un-

Subjects covered in the conference in­clude composites, ceramics, powder metallurgy, joining, coatings, monolithic metals, the socioeconomic and ecologi­cal aspects of new materials, interna­tional cooperation, and problems asso­ciated with standardization. A total of 53 papers were presented by authors from 12 countries. In the interest of better disseminating information about for­merly Soviet technology, this article fo­cuses on presentations by researchers from the Commonwealth of Independent States.

1993 April. IOM

cent. He noted that designers must be innovative in designing with composites; they must not just follow conventional metal design guidelines. In fact, he sug­gested that there is much to be learned from nature regarding effective designs using composites.

Balabuev concluded the presentation by suggesting that polymer composite structures require the use of automation for cost-effective production. This point was further emphasized in a question from H. Kelleser of Daimler-Benz, who noted that Western companies were not as enthusiastic about composite struc­tures as Balabuev because of their higher acquisition costs when compared to metal structures.

derscored the large amount of work be­ing performed on bioceramics, although little information on this work was re­ported at the conference.

Extensive studies are also in progress on superhard ceramics, including dia­mond-like compounds, some of which are alloyed with cubic boron carbide but maintain the diamond-like lattice. An interesting synthesis method is the ex­plosive sintering of these materials, which basically extends sintering as a densification technique to almost all materials. Trefilov concluded his re­marks by stating that Ukraine has an aggressive program in place to com­mercialize the various types of ceramics being developed.

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There is also activity on ceramic high­critical-temperature superconductors, which was discussed in detail by V.P. Seminozhenko, Institute for Single Crystals, Ukraine Academy of Science, in the presentation "The Problem of Developing High-Temperature Super­conducting Materials for Heavy Current Applications." He noted the difficulty in obtaining large monocrystals of the ex­tensively studied "1-2-3" superconduc­tor. He also discussed texture effects, including the use of silver wire coated with organic materials to orient needles of superconducting material.

ELECTRON·BEAM TECHNOLOGY

B.A. Movchan of the E.o. Paton Elec­tric Welding Institute, Kiev, presented "Electron Beam Technology: Processes, Materials, Coatings, and Equipment."

The Paton Institute has conducted much pioneering work in this area, and this progress was clearly demonstrated in the presentation. He noted three ma­jor developmental areas in electron-beam technology: melting, evaporation, and welding. Interestingly, although the Paton Institute is best known for its work in welding, Movchaninstead focused on melting and evaporation.

The Paton Institute has developed a number of innovative remelting tech­niques using electron beams. Movchan noted that, traditionally, melting using this method has been used for refining refractory metals as well as some nickel­and iron-based alloys. An interesting layer-by-Iayer melting concept employs a rotating billet, which is brought into contact with a molten liquid pool. A thin layer of metal solidifies, allowing pro­gressive build-up of the billet. The billet surface can then be deformed to produce a dense, fine-grained product.

Other melting developments include powder production from a rotating drum partially immersed in the molten metal and the direct production of strip and wire. These product forms can also be deformed immediately after formation for both microstructural and gauge con­trol purposes.

Electron-beam evaporation, followed by subsequent condensation, is carried out in high vacuum and yields uncon­taminated products. The evaporation rates reach 10-15 kg per hour, which is equivalent to a deposition rate of 100-150 Ilm per minute. One application is the coating of foil, strip, or sheet with relatively thick coatings (i.e., 1-2 mm). The forming of multicomponent alloys is possible from one bath, while two baths used simultaneously enable the formation of alternate constituent microlayers. Either of these product forms can again be deformed immedi­ately following production. Movchan noted that the evaporation and con-

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densation process allows the design of wide-ranging structures and properties.

Movchan also discussed dispersion­strengthened and microlayer and mi­croporous materials in some detail. Dis­persion-strengthened materials cur­rently under study include copper (strengthened with ZrB2 or molybde­num particles), aluminum, titanium, and titanium aluminides. Microlayered ma­terials consist of dissimilar materials with thicknesses that range from 100 nm to 100 Ilm or more and include mutually insoluble metal pairs (e.g., Cu-Mo, Cu­Fe, AI-Be) or metal-carbide or metal­oxide systems.

As an example of microlayered me­chanical properties, Movchan reported that with 200 nm layers of iron and cop­per, microhardness reaches 2.25 GPa. It is also possible to tailor physical char­acteristics, including thermal and elec­trical conductivity and thermal expan­sion coefficient.

Materials with controlled micropo­rosity, in the range of nanometers to micrometers, can be produced by vary­ing the substrate temperature, deposition rate, or additives.

The synthesis of intermetallics and refractory materials at much lower than normal temperatures has been proven possible by the use of condensation. For example, the author noted the formation of titanium carbide by the deposition of titanium and carbon vapor on a sub­strate heated to 650°C at rates of more than 100 Ilm per minute. A further de­velopment is the deposition of carbon with a diamond-like structure.

POWDER METALLURGY Ukraine

A paper by LM. Fedorchenko, pre­sented by V. Mikeilovich of Kiev's Ma­terial Science Institute, outlined the state of powder metallurgy (P 1M) work in Ukraine. The institute has played a ma­jor role in the P 1M field. Included in the presentation was an examination of friction materials and porous alloys. In the latter area, titanium-based materials and bronze have been fabricated for a variety of applications, including filters for cleaning oil, air, aggressive media, and tobacco fumes.

The presenter also discussed the use of P 1M in heat tubes and high-critical­temperature (up to 125 K) superconduc­tors. He also noted developments in dis­persion-strengthened materials for nuclear energy applications, where high stability (of strength and ductility) is necessary at intense radiation levels. Work is also being conducted on high­impact-resistance ceramics for potential use in gas turbine engines.

Applications of powder products in Ukraine include thermal coatings, ma­chine components, petrochemical use, and automotive parts. The Broveryplant

produced 30,000 tonnes of iron powder in 1990; another plant produced 2,000 tonnes of sprayed powder for cutting tool fabrication; at another location, 30,000 tonnes of ferrite powder were produced. In addition, titanium powder products are shipped to countries such as Austria and Germany.

It was suggested that conditions are favorable in Ukraine for expanding the P 1M industry. Specific areas for devel­opment are high-strength, high-ductility material with a fine grain size; increased powder production capability; high­speed steels using a P 1M approach; and new compaction and forming methods, including impact techniques and iso­thermal pressing.

Belarus

P.A. Vityaz delivered "Development of the Belarus Powder Metallurgy As­sociation in the Area of New Materials and Technologies: Their Application in Engineering Industries." The author re­ported that his organization-the Pow­der Metallurgy Institute in Minsk, Bela­rus--combined both scientific theory and production. Among recent advances are improved impact strength materials with increased density and aluminum alloys reinforced with SiC particulate. The latter materialis produced by extrusion to yield a homogeneous distribution of the sec­ond-phase particles.

Vifyaz also reviewed the production of inexpensive friction materials based on copper and iron. He also noted the fabrication of porous structures from bronze, titanium, niobium, and tantalum.

Work is also being conducted on highly porous metallic cellular material. Amor­phous and ultrafine powders are being produced by evaporation and conden­sation using plasma techniques.

There is also an extensive program on mechanical alloying to produce amor­phous materials, to perform dispersion strengthening, and to control grain size. The powders produced can be com­pacted by a variety of conventional techniques, including pressing and iso­static methods, as well as such newer approaches as hydrodynamic compac­tionand dynamiC explosive compaction.

Vityaz concluded the presentation by stating that the available P 1M methods allow microstructural features to be de­veloped in compacted material, thereby leading to desired phYSical and me­chanical properties.

F.R. Froes is director of the Institute for Materials and Advanced Processes at the University of Idaho in Mos­cow, Idaho.

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JOM • April 1993