VALVE FOR INTERNAL COMBUSTION ENGINE, ITS METHOD OF MANUFACTURING, AND THE HIGH-TEMPERATURE TITANIUM ALLOY FOR THE VALVE
The invention refers to mechanical engineering and can be used in piston internal combustion engines (ICE). The goal of the invention consists in increasing the reliability and lion-failure operation. of ICE valves, and increase of engine durability. 'the ICE valve has a stem off a constant diameter and a head in a disk form including a fillet portion, which ensures a smooth junction of the stern with the head. The ICE valve is made from a heat-resisting titanium alloy having (a+P) phase composition and the intermetallic a,-phase based on Ti,Al dispersed in the a-phase. The ICE valve consists of microstructures dissimilar both for the stem and head. To manufacture the valve a heat-resisting titanium alloy of which the composition (% by mass) being: (7.5-12.5) Al - (1.6-2.6) Mo - (1.4-2.4) Zr - (0. 142) Si - (0.05-0.1) Y - (the balance) Ti, is used. The method of manufacturing ICE valve is based on the use of deformation technologies and heat treatment. Deformation processing is carried out in two stages. At the first stage the stein microstructure is formed by cross and taper rolling. At the second stage deformation processing forms the valve head by forging. Before deformation processing the deformable part of the billet is heated. Preliminary heating of the deformable part of the billet is carried out under temperature control with the help of a. programmable controller.