| 摘要 |
<p>Ti coins are produced by cold-pressing Ti powder, under sufficient pressure to form a coin blank, the density of which is 60-90% of its theoretical density. The blank is stamped with stamping tools, at sufficient pressure, pref. (9.45-15.75) x 103 atmos., to yield a Ti coin, the density of which is >=90% of its theoretical density. Density control minimises erosion of stamping tools. Ti powder is non-toxic, easily available, and cheaper than Ni. High productivity can be achieved cheaply by powder-metallurgy. Dimensional control is easily carried out. Ti alloys with specific properties can be produced. Particles of other materials can be added before pressing. Density and conductivity can be adjusted. Ti retains its appearance for a long time.</p> |
