| 摘要 |
PURPOSE:To improve the productivity by shortening the time of a temperature rise by enabling a direct heating system device to manufacture diaphragms, by forming a discontinuous hard diffusion region by diffusion atoms, differing in kind from a metallic base, in its surface discontinuously. CONSTITUTION:Metallic base 1 of titanium foil formed in a desired shape previously is buried in boron-producing agent 9, containing carbon particles, in heat-proof chamber 4 and vacuum tank 7 is evacuated to produce a vacuum. Next, carbon particles in boron agent 9 are heated via heating electrode 10 to heat base 1. Then, boron atoms are diffused from the surface of base 1 and while the diffusion of boron atoms is not done at the contact part between base 1 and carbon particles, discontinuous hard diffusion region 8 is formed on the surface of base 1, so that the diaphragm of a speaker having prescribed ratio E/rho of Young's modulus E to density rho will be produced by the direct heating system. |
