A vacuum electron beam welding method

Abstract

The invention relates to a vacuum electronic beam welding method, which comprises (1), welding preparation that cleaning target material and back plate, and moving it into vacuum room to vacuum; (2), preheating welding seam; (3), the first vacuum electronic beam welding; (4), vacuum insulating temperature of target material; (5), second vacuum electronic beam welding; (6), quenching that taking out the target material from the vacuum room, and quenching. Compared with present technique, the invention insulates temperature after the first welding, to accumulate the H atoms on the welding seam to form air holes, then execute the second welding to remove said air holes, and it quenches the target material to avoid dispersing left H atoms, to effectively control the hole rate of welding seam.

Description

technical field [0001] The invention relates to the welding field, in particular to a vacuum electron beam welding method. Background technique [0002] In the field of semiconductor industry, for the manufacturing process of sputtering target products, it is usually necessary to weld high-purity aluminum or aluminum alloy targets that meet the properties of sputtering targets and high-strength aluminum rings, and then undergo rough machining and finishing. And other processes, and finally processed into sputtering target products with qualified dimensions. [0003] For sputtering targets, the surface temperature of the target after welding should not be higher than its recrystallization temperature, otherwise it will lead to changes in the size and orientation of the grains inside the target, and the thermal conductivity of aluminum alloy is particularly large, and the heat transfer is rapid. Only by using a very energy-intensive heat source can it be possible to ensure th...

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Problems solved by technology

[0004] For welding between high-purity aluminum and between high-purity aluminum and aluminum alloys, there is another problem: it is extremely difficult to control the porosity in the weld, because various methods are often used in the smelting stage to prevent the absorbed hydrogen from forming Pores exist in the material in the form of H atoms. When welding aluminum or aluminum alloys, the high temperature of the weld gives the H atoms enough energy to diffuse together to form pores. At the same time, due to the increase in the temperature of the weld, the solubility of hydrogen is sharp Rising, H atoms in the heat-affected zone around the weld will also diffuse into the weld, and hydrogen decomposed from external water, organic matter, etc. will also be absorbed by the weld, so when welding high-purity aluminum or aluminum alloy with electron beam Porosity in the weld is extremely difficult to control

Among them, repeated electron beam welding refers to repeated welding on the same weld. Its advantage is that it increases the storage time of the weld pool, making it easy for the gas to escape and reduce the porosity. The disadvantage is that repeated welding will lead to alloying elements. Burning loss, at the same time, the temperature of the heat-affected zone caused by repeated welding will greatly increase, resulting in deformation of the component, and after repeated welding several times, the porosity will decrease extremely slowly

Scanning welding means that when the electron beam moves along the direction of the weld seam, it also moves left and right in the direction vertical to the weld seam. The moving frequency is generally around tens of hertz. The stirring effect makes the gas in the molten pool easy to escape. The disadvantage is that scanning welding has a limited effect on reducing porosity and cannot fundamentally solve the reduction of porosity.

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