摘要 |
<p>A method of making a hollow article, for example, a hollow airfoil, from first and second preformed sections involves a first precursor (seal) bonding step where a low external pressure and internal vacuum are utilized to form a substantially gas impermeable seal bond between opposing bonding surfaces of the sections with only limited distortion of one of the sections and no distortion of the other section, a diffusion bonding step where a high external and high internal pressure is utilized to form a complete parent metal diffusion bond between the bonding surfaces without distortion of either section and an inflation step where a high external and high internal pressure are utilized to remove the limited distortion from the affected section without distortion of the unaffected section. The inflation step and diffusion bonding step can be combined into one operation to provide a two step method of making the hollow article. <IMAGE></p> |