Fatigue Behavior of Laser Surface Hardening for AZ31B Magnesium Alloy

The study has been implemented with the use of 4 groups; each group has fifteen samples, of laser surface hardening treated AZ31B Magnesium alloy. The first group has been as received specimens, the second group has been laser surface hardening with variable parameter of peak power (watt) specimens, third group was laser surface hardening with variable parameter of frequency (KHz) specimens and fourth group was laser surface hardening with variable parameter of pulse duration (ms)specimens. Fatigue tests are carried out at deflection value of(2, 2.5, 3, 3.5, and 4), and all these deflections transform into stresses. The stresses are (20.4, 25.5, 30.6, 35.7 and 40.8 Mpa).Equations as well as fatigue curves were recorded and determined with regard to laser surface hardeningofAZ31B Magnesium alloy treatment; also, the specimens have been subjected to hardness as well as surface roughness test. The results show that the laser surface hardening treated alloy groups in the case, when put to comparison with as received group fatigue. The as received specimens have a ductile fracture with high number of cycling, while the laser treated specimens have a brittle to brittle- ductile fracture and with a lower number of cycling. These are due to surface roughness and alloy brittleness.