Abstract:
The invention relates, according to a first aspect, to a process for the heat treatment of a cylinder head-type casting made from an aluminum alloy, in particular an alloy of aluminum, of silicon and of magnesium, and where appropriate of copper, comprising the steps of: —solution annealing (L) of the part for a time between three and ten hours; —quenching (S) of the part in air or in a fluidized bed; —tempering (H) of the part at the peak of resistance, or in the vicinity of the peak of resistance to attain a level of resistance of the part at least equal to 85% of the maximum level of resistance at the tempering temperature in question. According to a second aspect, the invention relates to the castings obtained at the end of the process according to the invention, and which have an improved fatigue resistance.
Abstract:
The invention concerns a method for casting a part made of metal alloy such as an aluminium alloy comprising the following steps: forming a core (N, PNC) having at least one shaft (PC) designed to form in the part a cylinder and at least one cavity (P) designed to form in the part a support and/or retaining zone for a working member, and at least a cooling unit (RE) proximate to the cavity; positioning the core in a metal mould cavity, and feeding the mould lined with its liquid alloy core by gravity. The invention is particularly useful for casting internal engine cylinder blocks with aluminium cylinders with improved geometrical and mechanical properties of the crankshaft bearing zones.
Abstract:
A thermal fatigue test stand for combustion engine cylinder heads. A cylinder head support having at least a cylinder head zone capable of being exposed to the engine combustion. At least one burner for directing a flame on the entire head zone. At least one heat flux sensor located in the cylinder head thickness at the zone to verify whether the heat flux produced by the flame is at least approximately in conformity with a predetermined value. The invention also concerns a method for calibrating such a test stand, and a method for testing cylinder heads. The invention is particularly useful for developing, both from a metallurgical and geometrical viewpoints, aluminum alloy cylinder heads.
Abstract:
A hypodermic syringe head with tamper-evident closure for a syringe barrel, having an injection cannula (4) which is mounted in a cannula carrier (5) from which it protrudes on both axial ends and which is disposed in a cannula carrier guide, so as to be movable relative thereto, and a cannula guard cap (1) , which is adjoined via a rated breaking point (2) by an anchoring element (3) that solidly holds the cannula carrier guide and can be affixed to the barrel neck, wherein a sealing disk (7) is received in the anchoring element, and two axially symmetrical guide grooves (15) for a guide peg (16) of the cannula carrier guide are embodied on the circumference of the cannula carrier, the guide grooves extending at a predetermined inclination substantially to form a V and opening into one another on their end toward the sealing disk, and in the unactuated state of the hypodermic syringe head, the guide peg engages the orifice region (15') of the guide grooves that is oriented toward the sealing disk, and upon a rotation of the cannula guard cap (1) in each of the two directions of rotation, the guide peg slides relative to one of the two guide grooves, destroying the rated breaking point.
Abstract:
The invention relates to aluminum alloy products containing 1 to 3.5% Li, up to 4% Cu, up to 5% Mg and up to 3% Zr, and additions of Mn, Cr and/or Zr, in which:Zn.ltoreq.0.10%, Mn.ltoreq.0.8%, and Cr.ltoreq.0.20%, ##EQU1## The alloy is recrystallized and has an average grain size of less than 200 .mu.m.
Abstract:
The present invention relates to Al-base alloys essentially containing additions of Li, Mg and Cu and possibly minor additions of Cr, Zr, Ti and Mn, which have high specific mechanical characteristics, a low density and good resistance to corrosion.The alloys according to the invention contain (in % by weight): Li 1.8 to 3.5; Mg 1.4 to 6.0; Cu 0.2 to 1.6 with Mg/Cu.gtoreq.1.5; Cr up to 0.3; Mn up to 1; Zr up to 0.2; Ti up to 0.1 and/or Be up to 0.02, Fe up to 0.20; Si up to 0.12; Zn up to 0.35%.The homogenization and solution treatments must be taken to a sufficiently advanced stage to dissolve the quaternary intermetallic phases (Al, Li, Mg, Cu) which are larger than 5 .mu.m in size. Such alloys present a compromise between their mechanical characteristics and their density, which is higher than that of the knwn Al Cu Mg alloys, and alloys containing Li.
Abstract:
The invention relates according to a first aspect to a method for the heat treatment of a batch of castings, in which an air quench is applied to the castings of the batch that are arranged in a single layer. The invention also extends to a system for the heat treatment of a batch of castings that includes a ventilation system in order to cause a flow of cooling air, characterized in that it includes means for placing the castings of the batch in a single layer and means for bringing the single layer of castings beneath the ventilation system so as to apply an air quench to the single layer comprising the castings of the batch.
Abstract:
The invention relates, according to a first aspect, to a process for the heat treatment of a cylinder head-type casting made from an aluminium alloy, in particular an alloy of aluminium, of silicon and of magnesium, and where appropriate of copper, comprising the steps of: —solution annealing (L) of the part for a time between three and ten hours; —quenching (S) of the part in air or in a fluidized bed; —tempering (H) of the part at the peak of resistance, or in the vicinity of the peak of resistance to attain a level of resistance of the part at least equal to 85% of the maximum level of resistance at the tempering temperature in question. According to a second aspect, the invention relates to the castings obtained at the end of the process according to the invention, and which have an improved fatigue resistance.
Abstract:
A process of fabricating a light alloy casting, such as an aluminum alloy casting, including at least one metal insert includes applying a coating of lampblack to a face of the insert intended to be in contact with the alloy of the component and casting the component with the molten alloy in a mold cavity in which the insert is positioned. Applications include fabricating engine blocks with integrally cast liners made of cast iron.
Abstract:
A method of heat-treating a casting made of an aluminum-based alloy including an alloy of aluminum, silicon, and magnesium comprising heat treating the casting at a first temperature range for a first duration; gradually cooling the casting to a second temperature having a second temperature range; maintaining the casting at the second temperature range for a second duration; quenching the casting; and age hardening the casting.