| 摘要 |
<p>Extra-hard watch case is of a metal boride material, pref. made by sintering a mixture of at least one metal boride and a metal or alloy. CrB2, TiB2 or ZrB2 can be used. Small quantities of Cr or Ni carbides may also be added. Scuffing is eliminated, and the specular polish is retained. Typical sinter mixtures are 35% stainless steel or 30-35% Ni with TiB2 or 20% Ni, 10% Co, and 70% of Zr and Hf borides.</p> |
