Question

joins parts by spinning and pressing them together
a. friction welding
uses a rotating tool to mix materials along a seam
b. friction stir welding
bonds surfaces using high - frequency vibration
c. explosion welding
d. ultrasonic welding

Explanation:

1. Matches the core mechanism of friction welding, which uses rotational motion and pressure to generate frictional heat for joining.
2. Friction stir welding uses a rotating non-consumable tool to stir and join material along a seam.
3. Ultrasonic welding uses high-frequency mechanical vibration to create frictional heat and bond surfaces.

Answer:

• joins parts by spinning and pressing them together: a. friction welding
• uses a rotating tool to mix materials along a seam: b. friction stir welding
• bonds surfaces using high-frequency vibration: d. ultrasonic welding