Multiple criteria are monitored and controlled to enhance the success of
direct-metal deposition, including greater control over factors such as deposit
layer height/thickness, sub-harmonic vibration, contour path shape, powder mass
flow, and deposition speed, and stress accumulation. Sensors are used to monitor
some or all of the following parameters during the deposition process: deposit
height, width, temperature, and residual stress. A predetermined limit with respect
to the yield strength of the material is preferably set. If the stress exceeds
that limit sensors will automatically introduce one or more remedial measures,
the priority of which is established using a look-up table generated in accordance
with prior experimental knowledge. To control temperature induced distortion and
stress, an infrared temperature detector may be used in conjunction with a controller
to reduce temperature, increase speed and decreased power for purpose of stress management.
