Patents Assigned to Deutsche Forschungs-Und Versuchsantalt Fur Luft- Und Raumfahrt E.V.
  • Patent number: 4531569
    Abstract: To produce tubes of reactive metals, a melt (14) is removed from the annu gap (13) of a crucible (10). The temperature of the melt (14) is such as to ensure the formation of the solidus-liquidus zone (33) directly behind the annular gap (13), a planar solidification front (34) being created in a non supported region which is not exposed to the direct influence of a cooling means. In the subsequent region, the oriented solidification of the tube with high temperature gradients is realized, and the tube can be shaped or adjusted free of thermal influences. Only thereafter, the tube (25) is exposed to the action of cooling means (26, 31) to cool it without contact. In such a way, it is possible to produce tubes having a high stability and resistance to temperatures for use in turbines, heat exchangers or the like.
    Type: Grant
    Filed: February 28, 1983
    Date of Patent: July 30, 1985
    Assignee: Deutsche Forschungs-Und Versuchsantalt Fur Luft- Und Raumfahrt E.V.
    Inventor: Klaus Fritscher