5-36. JOGGLING. Joggling of titanium can be accomplished without any particular difficulty provided the following rules
are adhered to:
The joggle die corner radius should not be less than 3T-8T.
Joggle run-out should be the determining factors whether joggles are formed hot or cold. Joggles should be
formed hot where a ratio of joggle run-out to joggle depth is less than 8.1.
Minimum joggle run-outs should be as follows:
Hot joggling four times the joggle depth.
Cold joggling eight times the joggle depth.
5-37. BLANKING AND SHEARING . These operations compare to those of 18-8 stainless steel in the ¼ hard condition
for commercially pure, and the alloys compare to ½ hard 18-8 stainless steel. The force required for titanium and its
alloys is greater and the dies wear faster. Materials up to 0.125 inch in thickness have been sheared on ½ inch capacity
flat bed shears designed for steel. If this capacity is to be exceeded, the shear designer should be consulted.
5-38. Before any forming or other operations are performed 0.025 inch of the sheared, blanked, sawed, or nibbed edges
should be removed to prevent stress risers that will cause a tear in the part during forming operations.
5-40. WELDING. Commercially pure titanium can be welded satisfactorily by fusion, seam and resistance spot welding
method; however, because of its affinity for oxygen, nitrogen, and hydrogen at welding temperatures, titanium becomes
embrittled and unworkable. To prevent this embrittlement and consequent loss in ductility, special precautions must be
taken, such as inert gas protection of the weld areas.
5-41. FUSION WELDING . Welding by the open fusion method can be accomplished provided that any air contact with
surface heated to 180°0F or above can be prevented. Welding can be effected by utilization of a sufficient quantity of
helium or argon or preferably a 50/50 mixture of both to shield weld zone. Alternatively an inert gas chamber which can
be constructed of ordinary sheet steel and fitted with observation windows and shoulder length rubber access gloves,
permits the fusion welding of titanium under ideal conditions. This chamber can be of any convenient size, should have
double seal gaslock doors, and can be mounted on a conventional welding table. The chamber should also be equipped
with a hose connection for the entrance of the inert gas and an escape valve to permit a constant flow of gas through the
chamber during the welding operation. It is suggested that the weld area be purged with the gas for approximately 30
seconds before the arc is struck and that a flow of 10 to 30 liters be maintained during welding. This flow of gas should
continue after the arc is broken until the color has disappeared from the weld. In selecting the inert gas to be used one
must keep in mind that helium permits a hotter arc and better penetration, whereas argon provides better control. A
satisfactorily protected weld has a bright silver color with no more than a slight straw to blue tint. Any sign of brown or
powdery white scale indicates insufficient shielding and must be corrected immediately upon detection. Uniformity of the
weld is best if direct current reverse polarity current supply is used, however, penetration and strength are equally good
with either alternating current or direct current.