Trends in the Development of Machinery and Associated Technology ” TMT 2010 , Mediterranean Cruise , 11-18 September 2010 EXPERIMENTAL DETERMINATION OF FORMING LIMIT DIAGRAM
Forming limit diagrams (FLDs) are a convenient and often used tool for the classification of the formability and for the evaluation of the forming process of sheet materials. Forming limits of sheet metal are represented in the forming limit diagram (FLD) occurring by various deformation states. The paper introduces a experiment method for determination of forming limit curve for whole range of the FLD for sheet metal.
Prediction of Thickness Distribution in Sheet Metal Forming by Modified Limiting Dome Height Test with and without Blank-Holding Force
This study aims to investigate the forming behavior prediction of AISI 1008 materials using Experimental Data and simulation. Forming behavior can be understood using thickness distribution also, by which strain localization and strain distribution in the sheet metal can be studied. In this present work, the difference in the thickness distribution for different drawing ratio i.e. D/d ratio is observed. The experiment has been done using modified limiting dome height test i.e. “LDH” for different case which includes Blank holding force and without blank holding force with different blank size. In LDH test, the mechanical properties are considered in different directions i.e. rolling direction (r0), perpendicular direction (r90) and transverse direction (r45). The strain paths are chosen from Two Different blank size from drawing to stretching condition; total points have been taken for the consideration of LDH test accordingly. Circle grid marking is done on the blank by laser marking and readings is taken in the different direction. Experimental work is compared with the software HYPERFORM for the validation of the work. Experiment’s thickness Data are obtained by taking reading at each circle grid. Thickness distribution are compared for better investigation of the formability among both the cases. Keywords— LDH test, circle grid analysiss, thickness distribution, hyperform simulation.
Phase formation during mechanical alloying in the Ti–Si system
Abstract Mechanical alloying of Ti–Si powder mixture or TiH 1.924 –Si powder mixture was performed by high-energy ball milling, in which the Ti to Si mole ratio was 1:2. The phase formations in both mixtures during milling were investigated by X-ray diffraction. Mechanical alloying a mixture of elemental powders led to the formation of TiSi 2 equilibrium compound, while when starting from Si + TiH 1.924 , a metastable phase was formed. The metastable phase completely transforms to TiSi 2 when the mechanically alloyed powder is annealed at temperatures above 800 °C. Two different pathways of phase transitions during mechanical alloying are attributed to the existence of hydrogen atoms, i.e., when starting from Si + TiH 1.924 compared to Si + Ti, the kinetics for the formation of the TiSi 2 intermetallic compound slows down. The kinetics related to the different phase transitions depending on the starting powder mixture are discussed.