Precise bonding of Cu micro-sphere

The beryllium-copper capsule is one of the candidate ignition capsules in National Ignition Facility Project. Precision match and bonding is the crucial process in the preparation for this capsule. In this paper, the technique is researched for the Cu materials as a substitute for Be, and the optimum parameters are achieved (temperature under 600 ℃, pressure less than 6 MPa, processing period more than 60 minutes). Finally, the Cu capsule is matched, with a surface roughness less than 50 nm and an asymmetry of diameters less than 20 μm. Using scanning electron microscope, cracks and flows have not be detected in the section of the joint. The strength of bonding meet the requirements of the following machining. (authors)