CD stud welding, using very short weld times, permits the welding of small-diameter studs to thin, lightweight materials. The weld cycle can be completed in 0.01 seconds on material as thin as 0.020" (0.5mm). These fast weld times minimize heat buildup, resulting in welds with very little distortion, discoloration, or burning. Therefore, this type of process is often used when appearance is a critical product feature.
The CD stud welding method, used mainly for welding mild steel, stainless steel,
and aluminum studs, includes two primary techniques: contact and gap. Both require
a specially designed stud with a projection, or ignition tip, on its weld end.
This tip provides accurate welding time control with precise repeatability.
CD stud welders use a capacitor storage system to produce a rapid electrical discharge, stud welding weld tools, and fasteners. No ferrules or flux are needed.
Contact CD Stud Welding
During this process, the stud is loaded into the weld tool and positioned in contact
with the workpiece. Energy is then instantaneously discharged from capacitors
through the stud projection. Since the size of the ignition tip cannot handle
the current density of the capacitor stored energy, it vaporizes, creating a
gap that allows an arc to be formed. As the arc begins to melt the stud and workpiece,
the two pieces are forced together, and a weld is produced as the metal cools.
Gap CD Stud Welding
Gap CD stud welding offers shorter weld times with higher current densities when compared with contact CD stud welding. With such quick welding capability, this technique is particularly well-suited to cosmetic applications, since it produces very minimal backside marking.
ADVANTAGES
This process creates high-integrity welds even on thin gauge materials. Additionally, it allows the welding of dissimilar metals because the weld penetration is so slight that metallurgical problems are prevented.
The quality, productivity, and cost advantages include:
Improved Quality
Attractive appearance with minimal burn – Often important in cosmetic applications, this process offers appealing one-sided welds with no reverse-side dimples.
Strength in lightweight applications – On very lightweight material that would be compromised when using other fastening processes, it creates a strong, high-quality bond.
Minimal backside marking – Allows backsides to be pre-painted without damage to the paint.
Productivity
Fast process – With its extremely short weld times, productivity is substantially increased.
Fewer assembly steps – Like drawn arc stud welding, CD eliminates punching, drilling, tapping, and riveting.
Economic Advantages
Labor savings – As in drawn arc stud welding, the CD welding process saves significant costs by eliminating through-hole preparation.
Fabrication savings – Often, an expensive, oddly-shaped piece can be duplicated.
Power Supply
The CD110 offers three user-selectable levels of capacitance. There are 66,000uf, 88,000uf, and 110,000uf levels that are selected via the top knob on the control panel. This allows the user to exactly tailor the power of the unit to the fastener being welded. This is like getting three different welders in one package.
CD APPLICATIONS
Providing quick welds on lightweight or thin gauge materials with little to no distortion, CD welding can be used for:
Jewelry – earrings and pins
Hardware – brackets, cleats, and tool handles
Cookware – utensils, pots and pans, and handles
Electrical Houseware – electric frying pans, cookers, oven assemblies, and microwave guides
Electrical/Electronic – components, terminals, pumps, motors, communication equipment, and electronic systems
Doors – commercial doors, escutcheon plates, and insulation
