| 摘要 |
PURPOSE:To prevent the residual stress at the time of casting and the cracking by fitting a ceramic top and outer metal together and cast covering them with an inner metal from inside to make the assembly integral. CONSTITUTION:A finished part of a ceramic top 1 and a finished part of an outer metal 2 are fitted together and an inner metal is casted thereto from its inside to make the ceramic top and the outer metal integral. An air gap 4' is spontaneously formed between the ceramic top 1 and the inner metal 3 through the contraction of inner metal 3 when it solidifies thereby creating a thermal insulating effect. |
