Abstract: The invention relates to a method for forming a lining on the walls of an inner pipe of a cast aluminium-alloy part, including inserting a cathode into the pipe, circulating an electrolyte solution in said pipe between the cathode and the walls of the pipe forming an anode, and applying a potential difference between the anode and the cathode, the method being characterised in that applying the potential difference between the anode and the cathode includes applying a series of DC voltage pulses to the anode. The invention also relates to a cylinder head in which the exhaust pipes are lined with a lining obtained by implementing said method.

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 present invention relates to a castable heat resistant aluminum alloy for high temperature applications such as components in combustion engines, in particular for the manufacturing of highly loaded cylinder heads, the alloy comprises the following composition: .Si: 6.5-10 wt %.Mg: 0.25-0.35 wt %.Cu: 0.3-0.7 wt %.Hf: 0.025-0.55 wt % Optionally with the addition of: .Ti: 0-0.2 wt %.Zr: 0-0.3 wt %, the balance being made of Al and unavoidable impurities including Fe.

Abstract: The present invention relates to a castable heat resistant aluminium alloy for high temperature applications such as components in combustion engines, in particular for the manufacturing of highly loaded cylinder heads, he alloy comprises the following composition: .Si: 6.5-10 wt %.Mg: 0.25-0.35 wt %.Cu: 0.3-0.7 wt %.Hf: 0.025-0.55 wt % Optionally with the addition of: .Ti: 0-0.2 wt %.Zr: 0-0.3 wt %, the balance being made of Al and unavoidable impurities including Fe.

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 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.

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.

Abstract: A write clock generation circuit is provided that can detect wobble signal in high accuracy and can appropriately generate write clock with only small jitter even when the operation is switched from reproduction to recording. The wobble signal is obtained by changing stepwise the gain of a variable gain amp in the rear stage of a divided photo detector using a gain control circuit in a predetermined time period just after the beginning of recording. The write clock signal is generated using the above wobble signal. According to this arrangements, the change in wobble signal just before and after the beginning of recording can be reduced, and the gain change of a wobble signal amplitude regulation AGC is made slow. As a result, high frequency deviation of the wobble signal can be reduced even when the operation is switched from reproduction to recording, and the write clock with only small jitter can be generated.