Abstract: A piston for internal combustion engines has a skirt coating, consisting of a wear resistant inner layer consisting of a polymer matrix having ceramic particles, aramide fibers and/or carbon fibers dispersed therein and an outer layer consisting of a polymer matrix having solid lubricants dispersed therein and an outer layer consisting of a polymer matrix having solid lubricants dispersed therein.

Abstract: produced according to the method having a piston crown with annular grooves, a combustion-chamber bowl, and piston shaft having a pin bore for receiving a pin, wherein both a combustion-chamber rim and a combustion-chamber bowl base are melted and thereafter solidified.

Abstract: A method for producing a one-piece, lightweight piston consisting of steel and having a small compression depth (S) forms piston with at least one cavity in a shaft aperture region. A piston blank is produced in a first step using a forging or casting method. To form a cooling channel between an annular region and a combustion chamber recess an annular section is formed in one piece onto the wall of a cooling channel in the vicinity of the piston base. The joint produced between the annular section and an outer wall of the cooling channel is sealed by welding.

Abstract: A method for producing a cooling channel system for an internal combustion engine, which has a cooling channel in the piston crown. The piston crown is adjoined by a lower piston part having a piston boss, pin bores and piston skirts. Firstly, a piston blank having a peripheral collar projecting radially in the region of the piston crown is produced, wherein the collar, forming a subsequent ring zone wall is then reshaped and, in a transition area between the piston crown and the lower piston part, a contact area for the collar is formed, and the collar is reshaped in such a way until the outer radially peripheral edge comes very close to or completely into contact with the contact area in order to form a closed cooling channel. Following the reshaping, the end region of the ring zone wall forms a defined gap (X) with respect to the upper edge of the piston skirt.

Abstract: A piston with a piston boss in which a piston-pin bore is provided for accommodating a piston-pin. The piston-pin bore widens in the direction of a piston of a piston inner area with the widening above a bore axis with regard to a piston stroke axis, is less than the widening below the bore axis or vice versa.

Abstract: A method for processing a constructed, liquid-cooled piston of an internal combustion engine, the piston including an upper piston part and a lower piston part, which are supported by a joining plane and are connected to each other in a bonded manner. An electrochemical method, such as electrochemical machining, is used to produce a passage opening or a hole in the piston. By means of the method, material is selectively removed after the completion of the upper part piston, the lower piston part, or the piston after the two piston parts have been joined. The electrochemical machining allows an arbitrarily geometrically designed topography having at least one passage opening, a hollow, or an oil pocket in cooling areas or non-cooling areas to be created on the piston.

Abstract: A piston of an internal combustion engine has a piston crown with annular grooves and a shaft part disposed on the piston crown. The shaft part has bearing shaft wall sections which are connected to one another via inclined connecting walls which are retracted with respect to the outer diameter of the piston. Piston-pin bosses for accommodating a piston pin are disposed in connecting walls. The connecting walls are retracted at such an angle that, in progressing from the lower edge over an intermediate region which lies further back than the lower edge, into an end region which lies further back than the intermediate region the connecting walls to over flush into a hub supporting region below the piston crown.

Abstract: A liquid cooled piston of an internal combustion engine includes a piston lower part and piston upper part which has a combustion chamber recess. These piston components are supported via joining lands which are spaced apart radially and together form a dividing plane, and are joined together preferably with a material-to-material fit. In order to receive piston rings, the piston upper part has a ring area and includes an annular cooling channel which extends into the piston lower part and is connected to an inner cooling space connecting channels. The cooling channel is adjoined by recesses which are oriented in the direction of a piston head, are configured as a blind hole and widen conically starting from the cooling channel as far as a recess bottom. The recess bottom can be of a pronounced undulating enlarged surface or a finely undulating configuration.

Abstract: A process for hardening an annular groove of a piston head of a piston of an internal combustion engine by means of laser beams, in which, at least the annular groove to be hardened is provided before or directly during the hardening process with a coating which absorbs the energy of laser beams. The coating is subsequently irradiated by the laser beams. The absorbing layer can be a manganese phosphate coating or is formed in situ by treating the component surface with a process gas comprising oxygen and inert gas. Furthermore, the laser beams are directed at the piston during hardening at an oblique angle to the direction of rotation. The advantages achieved are avoidance of reflections and undesirable hardening of the bottom of the groove, an increased degree of absorption and reduced distortion of the piston.

Abstract: A method for producing a piston of an internal combustion engine, wherein the piston has a combustion bowl including a combustion bowl rim. The combustion bowl rim is hardened by being remelted in a first step by means of an inductive energy supply and, in a further step, by a laser beam. The beam can be deflected during a rotary, progressive motion relative to the piston.

Abstract: A cooling channel piston has a radially circumferential cooling channel located behind a ring field. The cooling channel piston is forged from a steel material and the cooling channel is worked in by machining between an upper part below the ring field and a lower part above the piston bosses and the piston skirts. The cooling channel extends behind the ring field in the direction of an upper face of the upper part, it being provided that the cooling channel piston has above its piston bosses and piston skirts an outwardly oriented support region. A closing element, which closes the cooling channel after the production thereof, is fastened between the lower edge of the ring field and the support region.

Abstract: A piston, especially a cooling channel piston of an internal combustion engine, has an upper part and a lower part which can be produced separately from each other and subsequently be assembled. The upper part has at least three radially peripheral joining webs and the lower part likewise at least three radially peripheral joining webs. During assembly, the webs are put together and connect the upper part firmly to the lower part.

Abstract: The invention relates to a process for producing a piston of an internal combustion engine, wherein a piston blank is cast from an alloy of aluminium and silicon with the addition of copper fractions and is then finished, wherein the invention provides that the maximum fraction of copper in the alloy, of aluminium and silicon is 5.5%, and that fractions of titanium (Ti), zirconium (Zr), chromium (Cr) or vanadium (V) are admixed with the alloy of aluminium and silicon.

Abstract: A piston of an internal combustion engine includes a top part produced from steel and a bottom part, which are integrally bonded in the region of a contact geometry via joining webs by a friction weld to form a structural unit. At least one cooling duct permeated by a coolant is integrated in the piston, wherein a lubricating oil of the internal combustion engine passes as the coolant into an inlet opening via a free jet of an injection nozzle, flows through the cooling duct and leaves the cooling duct via an outlet opening. For the introduction of the coolant into the cooling duct, the inlet opening is assigned a flow pipe which is inserted in the bottom part and protrudes from a cooling duct base, the opening of the flow pipe being arranged above the weld beads of the friction weld.

Abstract: A flux for application on and for reduction of oxide layers on a metal surface. The flux includes potassium fluoride, sodium fluoride, remaining moieties of water and gelatin. The can also include a reactant comprising moieties of at least one of the compositions of zirconium fluoride, lithium fluoride, sodium fluoride, potassium cryolite and potassium aluminum fluoride (KaAlF4), moieties of salts on the basis of at least one of the elements zirconium, lithium, potassium, sodium, bismuth boron and titanium and gelatin. The flux can be used in a method to reduce oxide layers on a metal surface by applying the flux onto the metal surface.

Abstract: A piston has a piston head that is provided with a field of rings and a piston shaft which is disposed thereupon. The piston shaft is equipped with supporting shaft wall sections and rear connecting walls which interconnect the shaft wall sections, have an arched shape, and are fitted with a bolt bore. An undercut free space is provided below the annular field in the area of the bolt bore in the region of the piston head. An arched zone is disposed in the interior of the piston at the transition from the bolt bore in the direction of the shaft wall session.

Abstract: A method for producing a piston of an internal combustion engine, designed as a one-piece cooling channel piston. The piston includes an upper part and a lower part supported by corresponding circumferential joining bosses together forming a joining zone. In order to produce a bonded joint of the upper part and the lower part, the joining bosses are connected by means of multiorbital friction welding in the region of a rotationally symmetrical or rotationally asymmetrical joining zone.

Abstract: A method of producing a cooling channel piston for an internal combustion engine having a cooling channel in its piston crown, wherein a piston lower section with piston bosses, piston pin bores and piston skirts attach to the piston crown, wherein a piston blank is first produced with a circumferential collar radially projecting in the area of the piston crown, wherein the collar is then formed over, wherein, a seating area for the collar is formed in a transition zone between the piston crown and the piston lower section and the collar is formed over in such a way until its outer radially circumferential edge comes very close to or butts completely against the seating area to form a closed cooling channel.

Abstract: A method for producing a piston for an internal combustion engine, designed as a cooling duct piston for small compression heights. The piston includes a lower part and an upper part which are supported by one or more corresponding joining planes and are connected of a friction welding process. The piston encloses an inner, trough-shaped cooling duct and an outer cooling duct which is axially spaced apart from an annual area. The inner cooling duct is formed in the lower part of the piston by a mechanical machining process, such as a forging process. Transfer openings which are assigned to the cooling ducts are formed before the frictional welding of the joining planes.

Abstract: A cooling channel piston for an internal combustion engine which includes a piston bottom and a piston shaft that are joined thereto of a friction welding process. The piston bottom and the piston shaft jointly form a cooling channel. An annular wall which radially delimits the cooling channel towards the outside is formed by the piston bottom and/or the piston shaft. The annular wall can be sealed by a welding process once the piston bottom and the piston shaft have been joined together.