Hydrogen Treatment Of Materials Research Articles

A STEP ON THE ROAD TO HYDROGEN CIVILIZATION

The Third International Conference “Hydrogen Treatment of Materials” (HTM-2001), Donetsk, May 14–18, 2001 was the first international hydrogen meeting held under the effect of a new conception “From a Hydrogen Economy to a Hydrogen Civilization”, which was first developed by V.A. Goltsov and T.N. Veziroglu. That was a meeting of the representatives of three subcommunities of the world hydrogen movements: the hydrogen energy subcommunity, the hydrogen-materials subcommunities and the subcommunity of industrialists ensuring safety and efficiency of hydrogen use in terms of the up-to-date industry. More than 130 members from 60 organizations in the USA, Great Britain, Spain, Poland, Russia, Ukraine, Libya and Japan took part in the conference. Such a participation let the conference cover the achievements of hydrogen economy, hydrogen treatment of materials, and global subjects of a transition to Hydrogen Civilization of the future. At the final plenary meeting, the participants discussed and adopted the memorandum calling upon the world community, peoples and states to unite their efforts and to contribute with all the expertise attained to the transition of the humankind to the era of Hydrogen Civilization.

Transformations of Phases in Titanium Alloy after High Temperature Hydrogen Treatment

Positive nature of the effects of hydrogen on the properties of titanium alloys is manifested in the high temperature hydrogen treatment (HTM - Hydrogen Treatment of Materials), where hydrogen is temporary alloying component. The paper presents the results of the possibilities of hydrogen using as a temporary alloying element in Ti-6Al-4V alloy and titanium Grade 3. Treatment of hydrogen alloy consisted of three stages: hydrogenation in hydrogen gas atmosphere at 650°C, a cyclic hydrogen-treatment (3 cycles 850 °C to 250 °C) and a dehydrogenation in vacuum (550°C). It was shown that hydrogen affects appreciably changes the microstructure of surface layer of the tested titanium alloy. The aim of this work is to determine the effect of hydrogen on the two-phase microstructure in Ti-6Al-4V alloy and Grade 3 titanium and hardness after high temperature hydrogen treatment.

Effect of a High-Temperature Hydrogen Treatment on a Microstructure and Surface Fracture in Titanium Ti-6Al-4V Alloy

Influence of hydrogen on the structure of titanium alloys is a complex phenomenon, depending on the circumstances, may be negative or positive [1,2]. The presence of hydrogen in titanium alloys usually results in degradation of their microstructure and properties, as well promote some undesirable effects such as hydrogen corrosion and hydrogen embrittlement [3]. Positive nature of the effects of hydrogen on the properties of titanium alloys is manifested in the high temperature hydrogen treatment (HTM - Hydrogen Treatment of Materials), where hydrogen is temporary alloying component [4-9]. This is possible because of the high values of diffusion coefficients can be easily introduced into the titanium and it just as easily removed. Titanium and its alloys show the absorbability of almost 60 at. % of hydrogen at 600°C. The limit hydrogen of solubility in Tiα is very low and does not exceed 0.05 at. % at room temperature. The limit hydrogen of solubility in Tiβ is much higher and its maximum value is 48 at. %. Since the beginning of the titanium industry, a great deal of attention has been paid to control the hydrogen content at titanium products – above 0.2 ppm. The paper presents the results of the possibilities of hydrogen using as a temporary alloying element in Ti-6Al-4V alloy. Treatment of hydrogen alloy consisted of three stages: hydrogenation in hydrogen gas atmosphere at 650 °C, a cyclic hydrogen-treatment (3 cycles 650 °C to 250 °C) and a dehydrogenation in vacuum (550 °C). It was shown that hydrogen affects appreciably changes the microstructure of surface layer of the tested titanium alloy. The aim of this study is thus to determine the effect of hydrogen on the two-phase microstructure, hardness, and surface fracture of the titanium alloy Ti-6Al-4V due to high-temperature hydrogen treatment.

Changes of microstructure in titanium alloy during high temperature hydrogen treatment

The paper regarding the HTM - Hydrogen Treatment of Materials as an attractive method for controlling microstructure and improving final mechanical properties of titanium alloys. A new variant of high-temperature hydrogen treatment that includes cyclic heat treatment is proposed. This paper present the qualitative description of the microstructure in Ti-6Al-4V alloy after high-temperature hydrogen treatment with cyclic heat treatment operation. Hydrogen treatment consists of the three stages: hydrogenation in hydrogen gas atmosphere (600°C), cyclic heat hydrogen treatment (580°C), dehydrogenation in vacuum (550°C). The possibilities of hydrogen treatment for controlling microstructure layer of titanium alloy was presented.

Positive Hydrogen Effect in Structure Surface Layers on Ti Alloy

This paper presents the influence hydrogen effect in structure of surface layers on Ti-6Al-4V two-phase titanium alloys. It was described that hydrogen can be used as a temporary alloying element.The paper regarding the HTM - Hydrogen Treatment of Materials as an attractive method for controlling structure and improving final mechanical properties of titanium alloys. Hydrogen treatment consists of the three stages: hydrogenation in hydrogen gas atmosphere (600°C), cyclic heat hydrogen treatment (250°C), dehydrogenation in vacuum (550°C). This treatment uses purposeful, temporary introduction of hydrogen into the alloy to generate defects in its microstructure. Furthermore, it then causes recrystallization of defect microstructure during the dehydrogenation stage to grain refinement. This high-temperature treatment is very efficient for changing the microstructure and mechanical properties of two-phase titanium alloys.

Positive Effect of Hydrogen Treatment in Titanium Ti-6Al-4V Alloy

Positive nature of the effects of hydrogen on the properties of titanium alloys is manifested in the high temperature hydrogen treatment (HTM - Hydrogen Treatment of Materials), where hydrogen is temporary alloying component. This is possible because of the high values ​​of diffusion coefficients can be easily introduced into the titanium and it just as easily removed. Titanium and its alloys exhibit a high affinity for hydrogen absorption capacity, about 60% at. hydrogen at 600 °C. The hydrogen in titanium alloy is present in the form – an interstitial solution or titanium hydride. Since the specific volume of titanium hydride is about 13 ÷ 17% higher compared to α phase, it is high stress in the crystal lattice of this phase leads to local plastic deformation and large deformation phase. The paper presents the results of the possibilities of hydrogen using as a temporary alloying element in Ti-6Al-4V alloy. Treatment of hydrogen alloy consisted of three stages: hydrogenation in hydrogen gas atmosphere at 650 °C, a cyclic hydrogen-treatment (3 cycles 650 °C or 950 °C to 250 °C) and a dehydrogenation in vacuum (550 °C). It was shown that hydrogen affects appreciably changes the microstructure of surface layer of the tested titanium alloy. The aim of this study is thus to determine the effect of hydrogen on the two-phase microstructure, hardness, and corrosion resistance of the titanium alloy Ti-6Al-4V due to high-temperature hydrogen treatment.

Benefits and Drawbacks of Hydrogen Effect in Microstructure on Titanium Ti-6Al-4V Alloy

We present herein the effects of hydrogen on the microstructure of surface layers of two-phase titanium Ti-6Al-4V alloy. We describe the damage caused by hydrogen and the possibilities of using hydrogen as a temporary alloying element. The paper regarding the HTM - Hydrogen Treatment of Materials as an attractive method for controlling microstructure and improving final mechanical properties of titanium alloys. Hydrogen treatment consists of three stages: hydrogenation in a hydrogen gas atmosphere (600 °C), cyclic heat hydrogen treatment (300 °C), and dehydrogenation in vacuum (550 °C). We present the possibilities of hydrogen treatment for controlling the microstructure layer of titanium alloy and show results for the corrosion resistance of Ti-6Al-4V titanium alloy after hydrogen treatment. Information about the hydrogen effect on titanium alloys, based on selected publications and the authors’ experience, is also presented.

Hydrogen-induced diffusion phase transformations in Nd2Fe14B and Sm2Fe17 magnetically hard alloys

The Nd 2 Fe 14 B and Sm 2 Fe 17 magnetically hard alloys become thermodynamically unstable under the action of hydrogen and suffer hydrogen-induced direct and inverse phase transformations at elevated temperatures. The kinetics of these transformations is investigated. It is shown that they are diffusion-controlled and develop according to the mechanism of nucleation and growth. The hydrogen treatment of materials is a new branch of materials science [1] based on the specific features of hydrogen and hydrogen-induced phase transformations. In Nd 2 Fe 14 B- and Sm 2 Fe 17 -type magnetic materials, the hydrogen-induced diffusion phase transformations occur due to the different affinities of the atoms of different components of materials to hydrogen. Since the alloys consist of strong hydride- and nonhydride-forming elements, they lose their thermodynamic stability as a result of saturation with hydrogen. At low temperatures, these materials exist in the nonequilibrium (metastable) state. At elevated temperatures (T > (0.20 – 0.45) T m , where T m is the melting point), the diffusion of large atoms of the material becomes possible, and we observe the realization of hydrogen-induced diffusion phase transformations. The alloys decompose into rare-earth hydrides ( Nd H x or Sm H x ) and the α -phase of iron. In the Nd 2 Fe 14 B alloy, we also observe the formation of iron boride (Fe 2 B). The evacuation of hydrogen from the alloy after the direct transformation requires the thermodynamically inverse phase transformation resulting in the formation of the Nd 2 Fe 14 B or Sm 2 Fe 17 initial phase. As a result of the direct and inverse phase transformations, the microstructure is refined, which improves the magnetic properties of permanent magnets prepared from the alloys treated as indicated above [2]. In what follows, we generalize the results of investigations of the kinetics of hydrogen-induced direct and inverse diffusion phase transformations in the Nd 2 Fe 14 B or Sm 2 Fe 17 alloys and discuss the nature of these transformations within the framework of solid-state physics.

Hydrogen treatment of materials: Historical aspect and theoretical bases (review of the contemporary state)

The history of the development and contemporary state of the comparatively new field of materials science is reviewed: hydrogen treatment of materials (HTM). The action of hydrogen on materials is as marked as temperature, pressure, a stream of particles, and it includes four components: physical, chemical, physicochemical and mechanical. The technology of HTM is implemented extensively in practice and recently hydrogen heat treatment and hydrogen technology for titanium alloys, hydrogen treatment of an aluminum casting, and hydrogen treatment (HDDR-process) of alloys for permanent magnets have been formulated.

The hydrogen materials community: its history and current status in the World Hydrogen Movement

This review briefly summarises the history of the hydrogen materials community as an important part of the World Hydrogen Movement. It analysis the history and current status of the interrelation between the Hydrogen Energy (HE) and Hydrogen Materials (HM) communities. During the last 15 years, great advances in this cooperation have come about, thanks to the thorough activities of the Permanent Working International Scientific Committee on Hydrogen Treatment of Materials and the international conferences 'Hydrogen economy and hydrogen treatment of materials' under the auspices of the International Association for Hydrogen Energy (IAHE). The conclusion is that promoting this cooperation will be the responsibility of the World Hydrogen Movement in the 21st century, in general, and of nuclear HE technology, in particular.

Memorandum on a novel IAHE conception of a hydrogen civilisation of the future: historical aspects and the new challenges of the present day

This memorandum states: We, scientists, engineers, experts, industrialists – representatives of 28 countries, participants of the 5th International IAHE Conference 'Hydrogen Economy and Hydrogen Treatment of Materials, HTM-2007' (21?25 May 2007, Donetsk, Ukraine), representatives of the older and younger generations of the World Hydrogen Movement, taking into account that: the global energy and environment problems caused by fossil fuels continue to grow; fossil fuel resources are limited and Hubbert's peak will be reached in the near future; and the world scientific and cultural community is separated and consider the problems above from different (sometimes antithetical) viewpoints – and being active members of the World Hydrogen Movement and wishing to be of assistance in consolidating the world scientific and cultural community to successfully solve the problems above, discussed and adopted this full-scale memorandum on historical IAHE activities and the IAHE prognosis of the future humankind transition to the era of hydrogen civilisation and call on the world community to concentrate attention and activity on some new challenges of the present day.

Progress in hydrogen treatment of materials

A successful entry into the life of an ecologically clean hydrogen economy and an expected transition to hydrogen civilization in the future require the creation of new hydrogen-stable structural materials, new advanced functional ones, and new special technologies of their production and treatment. In response to these modern day requirements, world-renowned scientists and experts from 10 countries have contributed to this book — the first book reviewing the origin and development of the novel field of Materials Science and Engineering now referred to as ‘Hydrogen Treatment of Materials’ (HTM). The book generalizes the knowledge related to the HTM-theory and the HTM-technology. The structures and properties of material–hydrogen (MH) systems, their surface and subsurface layers, thin films and multilayers are considered. A diffusive–cooperative synergetic nature of MH-systems is generalized, their thermodynamic and kinetic peculiarities are analysed, and related phenomena are described. For the first time, there are systematically considered hydrogen-induced phase transformations: their nature, classification, mechanisms, kinetics, morphology, influence on structure and properties and use in the HTM. The present day knowledge is summarized as it relates to the HTM-technologies for deformed, cast and synthesized materials, such as palladium, niobium, vanadium, alloys on the base of Al, Ti, Fe, intermetallics, nonmetallic materials; the achievements of the HTM-technologies, improving their structures, mechanical, physical and catalytic properties are described. Some attention is also given to hydrogen degradation of metals, alloys and steels. The book is intended for Materials Science scientists, physicists, chemists, engineers and other active members of the world hydrogen movement. It will be highly useful for students, postgraduates and young scientists who are interested in the structure, properties and applications of material–hydrogen systems.

A step on the road to Hydrogen Civilization

The Third International Conference “Hydrogen Treatment of Materials” (HTM-2001), Donetsk, May 14–18, 2001 was the first international hydrogen meeting held under the effect of a new conception “From a Hydrogen Economy to a Hydrogen Civilization”, which was first developed by V.A. Goltsov and T.N. Veziroglu. That was a meeting of the representatives of three subcommunities of the world hydrogen movements: the hydrogen energy subcommunity, the hydrogen-materials subcommunities and the subcommunity of industrialists ensuring safety and efficiency of hydrogen use in terms of the up-to-date industry. More than 130 members from 60 organizations in the USA, Great Britain, Spain, Poland, Russia, Ukraine, Libya and Japan took part in the conference. Such a participation let the conference cover the achievements of hydrogen economy, hydrogen treatment of materials, and global subjects of a transition to Hydrogen Civilization of the future. At the final plenary meeting, the participants discussed and adopted the memorandum calling upon the world community, peoples and states to unite their efforts and to contribute with all the expertise attained to the transition of the humankind to the era of Hydrogen Civilization.

Hydrogen treatment (processing) of materials: current status and prospects

The hydrogen treatment of materials (HTM) as a novel field of Materials Science and Engineering is analysed and reviewed. First, a short history of HTM development is given. Then, the fundamentals of HTM are analysed and it is shown that hydrogen action on materials comprises physical, chemical, physico-chemical and mechanical components. In this aspect, hydrogen-induced phase transformations and their use in HTM are reviewed.

Hydrogen Treatment of Materials

Hydrogen Treatment of Materials

Fundamentals of hydrogen treatment of materials and its classification

A synthesis of knowledge is made in the new field of science and engineering, hydrogen treatment of materials (HTM), which is currently being intensively developed. Aims and tasks of HTM have been formulated. Fundamental bases of HTM have been analysed and summarized. Classification signs and some possible classification directions of HTM have been revealed. Some examples of hydrogen treatment of metallic and intermetallic materials are given.

Hydrogen Treatment of Materials

Hydrogen Treatment of Materials

The first international conference ?Hydrogen treatment of materials? (HTM'95)

The first international conference ?Hydrogen treatment of materials? (HTM'95)

First international conference on hydrogen treatment of materials (HTM—95), Donetsk, Ukraine, C.I.S., 20–22 September 1995

First international conference on hydrogen treatment of materials (HTM—95), Donetsk, Ukraine, C.I.S., 20–22 September 1995

First international conference on hydrogen treatment of materials (HTM—95), Donetsk, Ukraine, C.I.S. 20–22 September 1995

First international conference on hydrogen treatment of materials (HTM—95), Donetsk, Ukraine, C.I.S. 20–22 September 1995