Dynamic adjustment of friction stir welding process parameters based on weld temperature
AssigneeApple Inc.
InventorShravan Bharadwaj
Life of this patent
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Abstract
A method for friction stir welding is provided. The method may include beginning a friction stir welding operation by directing a rotating friction stir welding tool along a joint between two parts. A temperature of the resulting weld may be measured. Thereby, a controller may adjust process parameters associated with the friction stir welding process to decrease a difference between desired and measured temperatures of the weld. The desired temperature may correspond to a temperature at which the parts are plasticized. The process parameters may include rotational speed of the friction stir welding tool, feed rate, axial force along the length of the friction stir welding tool, and tilt angle of the friction stir welding tool.
Claims20
A friction stir welding method, comprising:
- directing a rotating friction stir welding tool along a joint between a first part and a second part to form a weld therebetween;
- measuring a temperature of at least one of a first part and a second part;
- and
- decreasing a temperature differential between the measured temperature and a desired temperature of the weld by dynamically adjusting one or more of a plurality of process parameters, the plurality of process parameters comprising an amount of axial force applied by the friction stir welding tool along the joint, a feed rate of the friction stir welding tool along the joint and a rotational speed of a tip portion of the friction stir welding tool,
- wherein the dynamic adjusting is in accordance with a temperature response curve that describes expected temperature changes in response to adjustments of at least one of the plurality of process parameters.
A system for friction stir welding, comprising:
- a friction stir welding tool configured to friction stir weld a first part to a second part along a joint;
- a motor configured to rotate the friction stir welding tool at a rotational speed;
- an actuator configured to apply an axial force along the friction stir welding tool against the first part and the second part and displace the friction stir welding tool relative to the first part and the second part along the joint;
- one or more sensors configured to measure a temperature of at least one of the first part and the second part;
- and
- a controller configured to dynamically adjust one or more of a plurality of process parameters in accordance with a temperature response curve to decrease a temperature differential between the temperature measured by the sensors and a desired temperature of the weld while the friction stir welding tool is directed along the joint, wherein the process parameters comprise the axial force, a feed rate, and the rotational speed of the friction stir welding tool,
- wherein the temperature response curve defines a relationship between changes in at least one of the plurality of process parameters and the measured temperature of at least one of the first part and the second part.
A non-transitory computer readable medium for storing computer instructions executed by a processor in a controller configured to control a friction stir welding system, the non-transitory computer readable medium comprising:
- computer code for directing a rotating friction stir welding tool along a joint between a first part and a second part to form a weld therebetween;
- computer code for measuring a temperature of at least one of a first part and a second part;
- and
- computer code for decreasing a temperature differential between the measured temperature and a desired temperature of the weld by dynamically adjusting one or more of a plurality of process parameters, the plurality of process parameters comprising an amount of axial force applied by the friction stir welding tool along the joint, a feed rate of the friction stir welding tool along the joint and a rotational speed of a tip portion of the friction stir welding tool,
- wherein the dynamic adjusting is in accordance with a temperature response curve that provides expected temperature changes of the weld in response to an adjustment of at least one of the plurality of process parameters.
Dependencies are inferred from the claim text.