Author : Dawood Selman, Khansaa
Engineering and Technology Journal,
2011, Volume 29, Issue 8, Pages 1610-1618
The research aims to study the effect of laser surface treatment on mechanical properties of CK45 steel which is widely used in Bolts, Axles Various,Connecting Rods and Hydraulic clamps. Trails of laser hardening were carried out by using CW Nd: YAG laser with different powers 2.7, 3.3, and 4.3 Watt. Mechanical tests were done for the specimens who were used in the research before and after treated by laser such as: Tensile test, Micro hardness. Also grain size measurement and microstructural evaluation were done by using
computerized optical microscope. The results show that improvement in
mechanical properties at laser power 4.3 watt obviously when compared with other laser powers. From tensile test we show that increasing in yield strength, ultimate tensile strength Poisson's ratio and plasticity constant (k). Also decreasing in Young modulus, Rigidity of modulus and strain hardening coefficient (n). While microhardness results show that the highest value was obtained at laser with 4.3
watt power and decreased far from the surface. Metallographic of the specimen show that refining in grains size after the treatment with laser.