It is now more than 100 years since certain detrimental effects on the ductility of iron were first associated with the presence of hydrogen. Not only is hydrogen embrittlement still a major industri al problem, but it is safe to say that in a mechanistic sense we still do not know what hydrogen (but not nitrogen or oxygen, for example) does on an atomic scale to induce this degradation. The same applies to other examples of environmentally-induced fracture: what is it about the ubiquitous chloride ion that induces premature catastrophic fracture (stress corrosion cracking) of ordinarily ductile austenitic stainless steels? Why, moreover, are halide ions troublesome but the nitrate or sulfate anions not deleterious to such stainless steels? Likewise, why are some solid metals embrit tled catastrophically by same liquid metals (liquid metal embrit tlement) - copper and aluminum, for example, are embrittled by liquid mercury. In short, despite all that we may know about the materials science and mechanics of fracture on a macroscopic scale, we know little about the atomistics of fracture in the absence of environmental interactions and even less when embrittlement phe nomena such as those described above are involved. On the other hand, it is interesting to note that physical chemists and surface chemists also have interests in the same kinds of interactions that occur on an atomic scale when metals such as nickel or platinum are used, for example, as catalysts for chemical reactions.

Zusammenfassung
Likewise, why are some solid metals embrit tled catastrophically by same liquid metals (liquid metal embrit tlement) - copper and aluminum, for example, are embrittled by liquid mercury.

Inhalt
Introductory Lectures.- General Overview: Atomistics of Environmentally-Induced Fracture.- General Overview: Atomistics of Surface Reactions.- Fracture - Applying the Breaks.- Tutorial Lectures on Fracture of Materials.- The Ideal Strength of Solids.- Physics of Fracture.- Mechanics of Fracture.- Fractography.- Tutorial Lectures on Surface Reactivity and Bonding.- Molecular Orbitals and the Atomistics of Fracture.- Cohesion and Decohesion in the Metallic Bond.- Theory of Chemisorption on Transition Metals in Relation with Heterogeneous Catalysis.- Relations between Fracture and Coordination Chemistry.- Hydrogen Adsorption on Metal Surfaces.- Adsorption on Metal Surfaces: Some Key Issues.- Interactions between Adsorbed Species and Strained Crystals.- Tutorial Lectures on Interfaces.- Nonequilibrium Surface and Interface Thermodynamics.- On the Structure of Grain Boundaries in Metals.- Interfacial Segregation in Multicomponent Systems.- Tutorial Lectures On Solution Chemistry.- The Solid/Electrolyte Interface.- Concerning Adsorbed and Absorbed Hydrogen on and in Ferrous Metals.- Electrochemically Obtained Information Concerning the Atomistics of Fracture in the Presence of Moisture.- Occluded Corrosion Cells and Crack Tip Chemistry.- The Growth of Surface Films in Electrolytes.- New Concepts in Atomistics of Fracture.- Computer Modeling of Cracks.- Electronic Processes at Dislocation Cores and Crack Tips.- Workshop Session 1: Hydrogen Embrittlement.- Hydrogen Related Fracture of Metals.- On the Transport of Hydrogen by Dislocations.- Contributed Papers:.- Hydride Formation and Redistribution in Zr-2.5 wt% Nb Stressed in Torsion.- The Hardening and Softening Induced by Hydrogen in Carbon Steels.- Diffusion of Hydrogen Near An Elasto-Plastically Deformed Crack Tip.- The Importance of Transient Effects Resulting from Dislocation Transport of Hydrogen.- Dislocation Transport of Hydrogen in Steel.- Hydrogen Assisted Crack Growth in High Purity Low Pressure Hydrogen Gas.- Effects of Crack Flank Oxide Debris and Fracture Surface Roughness on Near-Threshold Corrosion Fatigue.- Workshop Summary.- Workshop Session 2: Intergranular Embrittlement.- Atomistic Mechanisms of Intergranular Embrittlement.- Contributed Papers:.- About Intergranular Fracture of Hydrogenated Pure Metals.- Relative Effects of S, Sb, and P on the Intergranular Fracture of Iron and Nickel Tested at Cathodic Potentials.- A Comparative Study of the Influence of Rare Earth and Molybdenum Additions on the Temper Embrittlement Characteristics of a Low Alloy Steel.- The Effect of Sulphur on Hydrogen Recombination on Iron.- Workshop Summary.- Workshop Session 3: Liquid Metal Embrittlement.- Liquid and Solid Metal Embrittlement.- Nucleation and Egress of Dislocations at Crack Tips.- Workshop Summary.- Workshop Session 4: Stress Corrosion Cracking.- Stress Corrosion Cracking.- Contributed Papers:.- On the Propagation of Transgranular Stress-Corrosion Cracks.- The Embedded Disk Pressure Test (DPT): A Sensitive Technique to Investigate Materials Embrittlement.- H2S Adsorption on Plastically Strained Iron.- Workshop Summary.- Summary Session.- Atomistics of Fracture, a Conference Summary.- Contributed Papers:.- The Adsorbate-Substrate Bond and Stress-Relief Near a Crack Tip.- Crack-Tip Blunting versus Cleavage Extension.- A Comment on the Interpretation of The Griffith's Surface Energy in Terms of Lattice Vibrations.- Participants.- Photographs of Conference.