σ phase hardening

Laser phase transformation hardening

Laser phase trans-formation hardening

Laser Phase-change Hardening

laser phase-transformation hardening

Out-of-Phase additional hardening

Phase Transformation Hardening

Phase-change Hardening

ac nominal phase-phase potential transformer

ac phase-phase

phase-phase coupling

self-intensity of binding phase phase

Single-phase Phase-Locked Loop

Three Phase Phase-Locked Loop

Tri-Phase Phase Transfer Catalysis

three-phase phase-lock loop

3-phase thyristor phase shifting controller

6-phase Y-Y windings with 30 degrees phase displacement

all-phase time-shift phase difference