L'invention concerne un procédé de réalisation d'une surface satinée sur une pièce en un matériau présentant une dureté Vickers supérieure a 1000HV comportant au moins une surface polie, comprenant principalement les étapes suivantes:

- se munir d'un support pour la pièce et d'un laser à impulsion, dotés d'un mouvement relatif l'un par rapport à l'autre dans un plan XY,

- exposer localement la surface polie à une impulsion dudit laser apportant suffisamment d'énergie pour provoquer une fusion locale de la surface polie de manière à former un micro-cratère,

- répéter les impulsions du laser simultanément a un déplacement relatif de la pièce par rapport au laser, de manière à tracer des micro-sillons formés par l'alignement de plusieurs micro-cratères successifs se recouvrant partiellement, les micro-sillons étant sensiblement parallèles les uns aux autres et équidistants, et définissant ensemble la surface satinée.

The invention provides a roofing tile comprising: (a) a substrate; and (b) a coating disposed on said substrate, said coating resulting from hydration and hardening of a mixture comprising a hydraulic binder, said hydraulic binder comprising at least 60% by weight of a source of calcium aluminate and no more than 1% by weight of sulfate.

The invention also provides methods for making the tile.

Durability, acid resistance and freeze-thaw resistance are enhanced due to formation of a dense layer of hydrated alumina (AH₃) gel that fills the pores at the surface exposed to environmental impact.

A composition useful to provide oil repellency, water repellency, and stain resistance to substrates comprising a polymer prepared by contacting a polyfluoroalkyl sulfonyl halide with a compound of Formula II, III or IV



        Formula II: (E-(O)_q)₃Si-O-(Si(R²)₂-O)_m-[Si(R³-NHR⁴)(R²)O]_nSi-((O)_q-E)₃



        Formula III: HR⁴N-R³-Si(R²)₂-O-[Si(R²)₂-O]_m-[Si(R³-NHR⁴)(R²)O]_m[Si(R²)₂-(R³-NHR⁴



        Formula IV: HR⁴N-R³-Si(R²)₂-O-[Si(R²)₂-O]_m-Si-((O)_q-E)₃



wherein

each R² is independently a C₁ to C₈ alkyl,

each R³ is independently a divalent group containing carbon, oxygen, and

optionally at least one of nitrogen oxygen and sulfur,

each R⁴ is independently H or C₁ to C₈ alkyl,

each E is independently a C₁ to C₈ branched or linear alkyl,

each q is independently zero or 1,

m is a positive integer, and n is independently zero or a positive integer, such that n/(m+n) is zero or a positive fraction having a value up to about 0.7, and the polymer viscosity is less than or equal to 10000 mPa.s under a shear rate of 0.1 s^-1 at a temperature of 20° C.

A method of electrochemical treatment of prestressed concrete which comprises supplying a direct current between a steel embedded in the prestressed concrete as a cathode and an anode on the surface or inside of the concrete at a voltage higher than the hydrogen evolution potential, wherein an effective tensile force acting on the PC steel tendon embedded in the concrete is not greater than 80% of the tensile strength of the PC steel tendon, and a method of electrochemical treatment of prestressed concrete which comprises supplying a direct current between a steel tendon embedded in the prestressed concrete as a cathode and an anode on the surface or inside of the concrete at a voltage higher than the hydrogen evolution potential, wherein the voltage is adjusted to less than the hydrogen evolution potential at least once during electrochemical treatment, and then electrochemical treatment is resumed at a voltage not lower than the hydrogen evolution potential.

Le procédé de l'invention consiste à former un corps perméable au gaz (1) comportant des pores (28) ouverts, une première surface (2) destinée à être au contact d'un flux gazeux oxydant (4), susceptible d'oxyder le corps et une seconde surface (6) opposée à la première et à injecter un gaz protecteur (8) exempt d'oxygène à travers la seconde surface (6) entraînant des perturbations dans le matériau lui conférant une protection contre l'oxydation.

An ultra thin, water and oil repelling and durable overcoat is easily formed on a substrate surface via covalent bonding by applying a finishing agent of the invention, comprising a chemically adsorptive compound with a chlorosilyl group and a nonaqueous viscous liquid or solid medium, on the substrate surface. A finishing agent, comprising a chemically adsorptive compound with a chlorosilyl group and a nonaqueous viscous liquid or solid medium, is applied on a substrate surface comprising hydrophilic groups. The substrate surface is then reacted with the chemically adsorptive compound at room temperature, and the agent containing unreacted chemically adsorptive compound is removed. The generation of hydrochloric acid gas can be prevented by adding tertiary amine or amide in the molar amount of one to three times more than the chemically adsorptive compound contained in the finishing agent.

A diamond lattice substrate is irradiated with a high energy particle of sufficient flux, energy level and time period to irreversibly transform an area of a plane normal to the axis of irradition into conductive graphite. The substrate is cooled during irradiation to confine the graphite to the area of the plane at a desired depth within the substrate.

L'invention concerne le traitement d'un matériau sous forme oxyde en vue de faire varier sa stoechiométrie anionique ainsi que les produits obtenus par celui-ci.

Le traitement peut être appliqué aux supraconducteurs, aux matériaux à comportement semi-conducteur ou métallique, ou aux précurseurs de tels matériaux.

Ledit traitement consiste à utiliser le matériau sous forme d'électrode lors d'une électrolyse dans un milieu liquide, notamment neutre ou basique.