Development and optimization of laser engineered super thick novel surfaces for extreme temperature applications
Development of defect free sound surfaces with exceptionally good functional characteristics such as high fatigue strength, hardness and wear resistance for severe working conditions (extreme temperatures and structural loads) is one of the main objective of surfaces processing engineering. Several manufacturing methods can be employed to develop such hard facing surfaces on an ordinary substrate but laser cladding is a highly preferred commercial process for such applications due to superb control and variations of processing parameters. In laser cladding process, a laser beam is used to fuse powder materials with substrate which differ from each other due to different metallurgical properties, during the cladding process a very thin layer of the substrate is melted in order to achieve metallurgical bonding with minimal dilution of added material and substrate so that the original properties of the coating material are maintained. Laser cladding process has excellent bonding characteristics as compared to conventional manufacturing techniques such as plasma. Due to limited dilution and heat affected zone (HAZ), developed coating surfaces readily achieve the desired functional properties.
Prime objective of this MSc. thesis is to develop defect free novel materials (various tool steel grades) coatings on steel substrates and the identification of optimized processing windows by using laser cladding process. The processing of these coatings involves high level understanding of various simultanously intereacting processing parameters and their subsequent affects. Major processing parameters are laser power, laser scanning speed and powder feeding rate. The qualification and post-analysis of developed coatings will be performed with close collaboration of industrial partners. Experiments will be conducted at laser laboratory of Chair of Applied Laser Technologies (ALT). The prime objective of the project is divided into following listed sub-objectives.
1.Cladding of single layer/ multi layers/ stacked up layers on a plate and cylinder
2.Identification of optimum laser / inductive pre-heating
3.Varying the clad solidification cycle to achieve various grain sizes and properties
4.Development of various coating paths by programming the ABB robot especially for stacked up layers to minimize the residual stresses and process defects
5.Development of laser cladding setup by updating it with new possible powder feeding and data acquisition systems
6.Laser power ramping with constant clad temperature and melt pool size
7.Cross sectional analysis and hardness measurement of clad layers
8.Experimental measurement of residual stresses (strain) by hole drilling, layer removal and anyother possible experimental technique to validate the inhouse developed FEM
Few preliminary and essential tasks are listed below, while further associated tasks will be assigned during the project work to successfully achieve the core research objectives.
§Detail literature review
§Compulsory training of laser cladding setup including control of ABB robot and manipulator, 4000W ND YAG laser, powder feeding and data acquisition systems
§Design of experiments followed by analysis and optimization
§Critical analysis of experimental outcomes and subsequent affects
§A poster presentation of performed experiments and results
§Writing MSc. thesis, and preparation of thesis defence
§Weekly progress meetings with supervisors
Commencement and Duration
§Duration: Equivalent to 40 EC
§Dr.ir. G.R.B.E. Römer (firstname.lastname@example.org)
§MSc. N. Ur Rahman (email@example.com)