Titanium Alloy Forging Blanking Process

For titanium alloy forging, because the material is expensive, it is more suitable for forging and forming, which not only improves the internal quality of the component, but also saves metal materials. Every aspect of forging affects more or less the internal quality or appearance quality of forgings. Therefore, each process must be completed strictly in accordance with the forging process.
Forging of titanium alloy is expensive, it is more suitable for forging and forming, which not only improves the internal quality of components, but also saves metal materials. Every aspect of forging affects more or less the internal quality or appearance quality of forgings. Therefore, each process must be completed strictly in accordance with the forging process.
Forged (rolled) rods for titanium alloy forging have a hard and brittle α layer on the surface. Before die forging, this layer needs to be removed to avoid cracking of the blank surface during forging. For rods with a diameter of less than 50mm, the 3mm thick surface layer needs to be removed, and for diameters greater than 50mm, 5mm needs to be removed. For extruded bars, if the diameter is less than 50mm, it can be 2mm, and if the diameter is greater than 50mm, it is generally 3mm. After turning, if there are still defects in individual parts, local grinding can be carried out to eliminate, the grinding depth should not be greater than 0.5mm.
Forged forging titanium alloy blanks can be cut with sawing machine, lathe, anode cutting machine, punching machine, grinding wheel cutting machine or on forging hammer or hydraulic machine. The cutting efficiency is the highest on the punching and shearing machine.
(1) The thickness of the circular saw cutting disc saw blade is between 2 and 8 mm, which is suitable for cutting bars with larger diameters. The linear speed of the circular saw is about 30,000 ～ 35000mm / min, and a relatively clean end face can be obtained when the feed amount is small. In order to prevent the metal from sticking to the tool and burning the metal, the suspension can be used to reduce friction and cool the tool.
(2) Anode cutting The titanium alloy anode is mechanically cut, the width of the cut does not exceed 3mm, and water glass with a concentration of 1.28 to 1.32g / cm3 is used as the working fluid. Although the anode cutting has less cutting consumption, the rate of birth is low.
(3) Before cutting on a hammer or a hydraulic press, the bar material must be preheated to the deformation starting temperature for punching (or chopping). Industrial pure titanium can be cold cut on punching and shearing machine.
(4) When turning a titanium alloy on a lathe, the cutting speed should be within 25,000 to 30,000 mm / min, and the feed rate is 0.2 to 0.3 mm / week.
When peeling the skin to remove the α layer, the turning specification is: cutting rate 15000 ～ 20000mm / min. The turning specifications without the α layer are related to the surface roughness: when the roughness Ra = 0.63 ～ 2.5, the infeed is 0.08 ～ 0.1mm / week; when Ra = 1.25 ～ 5, the infeed is 0.1 ～ 0.2mm / Week; when Ra = 2.5 ～ 10, the feed rate is 0.3 ～ 0.4mm / week. When turning, lubricating coolant must be used to supply pressure of 1 ~ 1.5MPa.
(5) When the diameter of the titanium alloy bar is less than 60mm, it should be cut with a grinding wheel. When the diameter of the grinding wheel exceeds 20mm, coolant should be used. The cutting efficiency of the grinding wheel is higher, but the life of the grinding wheel is shorter.
After cutting the blank, the sharp angle of the end should be rounded. Otherwise, it may cause folding when performing end face forging or pushing up on a horizontal forging machine. For blanks with a diameter of less than 50 mm, the radius R for acute angles is 1.5 to 2.0 mm; for blanks with a diameter of more than 50 mm, the radius R for acute angles is 3 to 4 mm.
When manufacturing particularly important parts (such as blades), after the outer circle of the bar or fixed-size blank car, an ultrasonic inspection should be performed to find internal defects.