Papers by Venkateswarlu Devuri
Present work describes friction stir welding of in-house produced and hot rolled Al-4.5%Cu/TiC in... more Present work describes friction stir welding of in-house produced and hot rolled Al-4.5%Cu/TiC in situ metal matrix composites by using hardened bimetallic tool with varying shoulder surface geometries and other process variables. Joining of the said composite using friction stir welding process has been seen to provide beneficial effects such as grain refinement of the matrix and subsequent redistribution and refinement of reinforcements. A predictive model has also been developed to estimate the weld properties such as tensile strength and ductility with respect to the tool geometry used and input process variables. The X-ray diffraction analysis results of Al-4.5%Cu/TiC butt welds indicated formation of CuAl 2 O 4 and CuAl 2 to some extent in the stir zone. Fractography of the weld samples revealed dimpled ductile nature of fracture. Through multi response optimization of the welding parameters and tool geometry, weld strength of 89% that of the base material was achieved.
The weld properties of frict ion stir welding remains as an area of interest with respect to the ... more The weld properties of frict ion stir welding remains as an area of interest with respect to the effect of tool geometry and process parameters. In the present investigation effort has been made to understand the effect of important weld ing parameters such as tool rotational speed, traverse speed and probe geometries on various mechanical properties of AA1100 alu min iu m alloys. Ultimate tensile strength, percentage of elongation and hardness were determined experimentally for this purpose. Analysis of variance (A NOVA) was used to observe the main effect of above mentioned parameters on mechanical properties. A regression relationships were developed to predict each output. The experimental and pred icted values from the mathemat ical model were in close agreement.
The stirring action and solid state nature of friction stir welding process provide interesting p... more The stirring action and solid state nature of friction stir welding process provide interesting possibilities for very fine refinement and redistribution of in situ reinforcements in the grain refined metal matrix. The present investigation discusses the effect of varying process parameters on friction stirred butt welded hot rolled Al + 12%Si/10 wt%TiC in situ composites. A bimetallic tool with flame hardened titanium alloy probe was used in the experiment. The tool shoulder dimension, welding speed and tool rotational speed were varied during welding to study their effects on the ultimate tensile strength, percentage elongation and micro-hardness of the butt joints. Plan of full factorial design was followed for producing the Al + 12%Si/10 wt%TiC butt welds. The friction stirred weld zone of the aforementioned composite exhibited grain refinement of the matrix as well as refinement and uniform redistribution of in situ reinforcements. The average value of the micro-hardness in the weld zone varied significantly with respect to the process parameters and tool design. The ultimate tensile strength of the weld joints also varied from 124.23 MPa to 171.74 MPa based on the process parameters and tool type. The desired outputs were also optimized as per the multi-response desirability function-based technique. The observed 0.07-2.98% error in the optimality test results witnessed the adequacy of the adopted optimization technique.
Uploads
Papers by Venkateswarlu Devuri