Effect of Laser Surface Treatment on Mechanical Properties of CK45 Steel

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

Effect of Laser Surface Treatment on the Properties of Composite Material Produced by Powder Technology

In this investigation we obtained composite material by the powder technology process of metallic matrix which posses particle size ( 20µm ) with changing the percentage of additive ceramic material which posses particle size ( 53 µm) which is widely used in aerospace vehicle ,medical and engineering applications. Macro hardness and physical properties (density ,porosity), also microstructure which were produced from laser surface treatment of the composite material were done into two stages: 1- To study the first stage: study the effect of the changing in the percentage of the additive ceramic material SiC (%5 ,%10 ,%15 ,%20 ) on hardness and physical properties of composite material before and after sintering of the specimens. 2-The second stage :The study the effect of laser surface treatment on hardness and physical properties with different percentages.Pluse Nd:YAG laser was used with frequency ( 3Hz ),wave length (1064nm), laser energy ( 1J ) and pluse width (100 nm) and study the effect of one pluse and two pluses on hardness after sintering of the specimens. The results which were obtained experimentally reveals the impovment in the structure and hardness and also the physical properties (density ,porosity) for the specimens treated by laser with two pluses and additive percentage (%20 )

One Parameter Composite Semigroups of Linear Bounded Operators in Strong Operator Topology of Schatten Class Cp

For semigroups of linear bounded operators on Hilbert spaces, the problem of being in Cp , 0 Keyword