المعاملة السطحية بالليزر لحديد الزهر الرمادي باستخدام ليزر (Nd : YAG - Nano Second) == Laser Surface Heat Treatment For Gray Cast Iron Using Nano Second Nd : YAG Laser
Author name:
بلال احمد حبيب
Supervisor name:
رابحة صالح ياسين | هجران زين العابدين طعمة
General topic:
Production engineering metallurgy and materials
Specific topic:
Metals Engineering
Degree:
Master
University:
University of Technology
Language:
English
University location:
Baghdad
First pages:
50T181 - p.pdf
Abstract:
في هذا البحث، تم استخدام تاثير معلمات الليزر لتحسين الخواص السطحية للحديد الزهر الرمادي، وذلك باستخدام جهاز Nd : YAG ليزر بطول موجي nm(1064 (، البعد البؤري cm( 5 ,10,18)، وامد النبظة ns (10). استخدمت طريقة الانصهار السطحي بالليزر في تصليد العينات، الى | In this thesis , the effect of laser parameters is used for perfection of the surface characteristics for gray cast iron , using pulsed Nd : YAG laser with wavelength of (1064nm ).The laser surface glazing and shocking methods have been used in hardening the specimens , besides using the laser energy in treatment of (1.2 J) , pulse duration (10 ns), with different focal length of (5,10,18) cm and used the (air ,water , DMSO) as a active medium. In laser surface engineering the micro hardness, roughness and wear rate examinations deliberated before and after laser treatment. The effect of laser parameters includes : The effect of the pulse repetition rate (P.R.R) , the result shows , thevalue of the micro hardness of work pieces reduced but the variation in the value hardness decreased. For the effect of the medium used (air, water, DMSO) it was found with increasing the water and DMSO high the value of the micro hardness of work piece increased and value of the (loss of weight , wear rate, surface roughness ) reduced. After treatment by laser the amount of loss in weight is less than the loss of weight with the base metal (before the treatment) , so the results reveal an improvement in wear rate after treatment by laser. And for the effect of overlapping technique ,it was found that the best percentage for overlapping technique ratio is 50% for the selected laser energy. The value of micro hardness increased by moving away from the center of the laser strike on the work piece.
