ÖMER TAYLAN BOYA 030070099 10th WEEK

Canadize (titanium) (in Magnaplate) (11:31 am 15.04.2011)

--A system for hardfacing each material has been developed which is basically an electrochemical process. The synergistic coating system is still far the best for a wear application, however, and special fluoropolymers or dry are infuesed into the hardfacing.
--For titanium synergistic coating is called Canadize. For titanium application thickness is difficult to build up, so the normal application thickness is between 0.0002 and 0.0005 in.
--A classic application for Canadizing is titanium hardware for aircraft. Such components are anodized with an infusion to a thickness of 0.0002 - 0.0004 in. to prevent the titanium from seizing.

(Donates Satas, Coating Technology Handbook 2nd edition revised and expanded, page 308)

Babbiting (about coating) (13:57 pm 15.04.2011)

--Babbitting consists of attaching a layer of softer metal (usually a tin-lead composition) to a part of much sturdier composition which acts as a supporting element. The soft layer, or the babbitt, has excellent antifrictional properties. In shafts, the babbitt averts galling and scoring of the surface, while the inner, stiff core acts as its support in torsion, when rotating.
--Babbitting is used with bearing shells, hardware elements, automotive connecting rods, jewelry, and numerous other applications. The babbitt is attached to the supporting metal by either of two methods:
• Mechanical bonding of babbitting is performed by using fasteners, dovetails, and other grooves.
• Heating of the babbitting material along with its supporting part and allowing the assembly to first cool at the area of contact between the babbitt and its support. This method is useful with shells, where the babbitt is introduced in the form of a mandrel.

(Ivana Suchy, Handbook of die design , page 678)

In-Die Welding (14:08 pm 15.04.2011)

--In-die resistance welding has lately achieved a large popularity. Years ago, nobody even dared to think about attaching a spot welder to the progressive die and produce welded assemblies right there, automatically. But then, we must realize that years ago, sensors were not as common as they are nowadays, and without sensors in-die welding may not be possible.
--Sensors in the in-die welding process are necessary to ensure a total protection to the die. A thorough monitoring of parts’ feed length, die components’ position, scrap removal, and the overall die function as combined with the control of the moving strip, is essential. The welded-on objects must be monitored for their proper positioning within the die to make sure the welding electrode will engage the material right where it was planned and exactly the way it was planned.
--The amount of pressure the upper electrode exerts toward the assembly-to-be-welded must be carefully monitored as well, and this information must be reported back to the PLC controller. This pressure is necessary not only to hold the parts in place, but to provide for a firm contact of the two, so that welding can occur. Without a positive contact of the components, a resistance weld is very difficult to produce. As can be easily imagined, oil, grease, or dirt on the surfaces may impair the weld quality.

(Ivana Suchy, Handbook of die design , page 507)

In-Die Tapping ( 14:13 pm 15.04.2011)

--In-die tapping, not long ago considered impossible to achieve, is quickly becoming an industry standard. So far, the on-going research came up with three different types of tapping systems:

• Tapping with an external lead screw
• Tapping with an internal lead screw
• Tapping with a rack and pinion system

--External lead screw systems use a series of gears, which are driven by a helix lead screw on descent of the press ram. The lead screw does not rotate; it only drives the gear assembly to generate and transfer the motion necessary for a tap cartridge to produce the thread. The length of the travel of the tap cartridge with respect to the ram travel is adjusted by changing the gear ratio. The gears are further adjustable to accommodate for a different thread pitch; they can tap downward or upward, vertically, horizontally, or under any angle.
--Internal lead screw systems depend on a cam for transfer of the ram travel into tapping of openings to specified depths. Here the lead screw rotates when driven by the roller nut on its way down. The system can be designed as vertical or horizontal, with dependence on the preferences of the user.
--Rack and pinion system of in-die tapping is similar to the external lead screw system, the difference being in a rack and pinion replacing the helical lead screw. Multiple tapping units can be attached with chain drives to the main drive system.

(Ivana Suchy, Handbook of die design , page 504)