Quantification of Qualitative Defects for Automobile Customers -2014-

 

Effect of size and strain rate on deformation behaviour of Cu50Zr50 metallic glass: A molecular dynamics simulation study

Dhal, Satyanarayan and Yadlapalli, Raja (2012) Effect of size and strain rate on deformation
behaviour of Cu50Zr50 metallic glass: A molecular dynamics simulation study. BTech thesis.

PDF 2367Kb

Abstract

Metallic glasses or amorphous metals have attracted considerable attention due to their unique properties and have been evolved as a potential field of research in recent years. The recent discovery of new glass-forming compositions makes it possible to produce metallic glasses in bulk shapes. Bulk metallic glasses provides a promising future to revolutionize the field of structural materials with combinations of strength, elastic limit, toughness, wear resistance and corrosion resistance. Some of their superior properties over crystalline metals have made them a versatile engineering material for many commercial applications now-a-days. Since the fabrication of metallic glasses require high cooling rates and sometimes practically impossible in laboratory conditions, so computational approaches are extensively used to explore various properties and behaviour of metallic glasses.
This project work presents a molecular dynamics simulation study on deformation behaviour of Cu50Zr50 metallic glass where the effect of parameters like sample-size and strain rate on the tensile deformation behaviour have been thoroughly studied. Computational methods to create alloy models, subsequent quenching and further tensile deformation have been mentioned. Stress-strain plots were drawn at same strain rate for different sizes of alloy models and at different strain rates for a particular size. Reasons for getting different stress-stress curves for different conditions have also been discussed.

Optimization of Flow Characteristics of Blast Furnace Slag

Dash, Supratik and Mohanty, Nachiketa (2012) Optimization of Flow Characteristics of Blast Furnace Slag. BTech thesis.

PDF 1429Kb

Abstract

A study of the flow characteristics of blast furnace slag is important to record the softening and melting phenomena in blast furnace which greatly influence the extent and location of the cohesive zone having a direct say on the blast furnace operation, quality of hot metal and the coke consumption. In the present work, a noble technique (heating microscope) is adopted to determine the flow characteristics of blast furnace slags obtained from different blast furnaces. It is seen that the results so obtained agree very closely with the values obtained from adopting conventional methods of determining the same using the slag atlas. It is also seen that the characteristics temperature are altered with the alteration of C/S ratio and also the MgO content of the blast furnace slag.

Effect of copper on the properties of austempered ductile iron castings

Behera, Gourahari and Sohala, Soumya Ranjan (2012) Effect of copper on the properties of austempered ductile iron castings. BTech thesis.

PDF 2674Kb

Abstract

Two types of ductile iron has been taken for the present investigation. Both austempering time and temperature are considered as the main variables for structure property correlation of Austempered Ductile Iron. The two types of spheroidal graphite iron (differ by copper percentage) were austempered at four differing austempering temperatures viz. 250oC, 300oC, 350oC and 400oC for 60min, 90 min and 120 min respectively. The effect of austempering variables on the mechanical properties of spheroidal graphite iron was investigated as a function of austempering time and temperature. The cooling rate and the quenching techniques followed in the present study plays an important role for the property development of spheroidal graphite iron. The tensile properties have been correlated with the graphite morphology for both grades of ADI. SEM micrographs have been taken from fracture surfaces of the tensile specimen under different austempering conditions. It has been found from the result that ADI having the alloying element (copper) achieved significant mechanical properties as compared to ADI without having copper throughout the different austempering processes adopted in this study.

Synthesis and Characterization of Al-4.5%Cu Alloy Powder Using Mechanical Alloying

Anand, Kshitiz and Vadlamoodi, Kishore and Roy , Seshadri Deb (2012) Synthesis and Characterization of Al-4.5%Cu Alloy Powder Using Mechanical Alloying. BTech thesis.

PDF (Mechanical Alloying) 1270Kb

Abstract

The present work aims to improve the mechanical properties of Duralumin (Al-4.5 wt. % Cu) alloy produced by mechanical alloying and consolidated using conventional isotactic hydraulic compressor. A uniform dispersion of SiC and TiO2 reinforcements tends to improve the mechanical properties of the present alloys. The current alloys show xtraordinary hardness values which are 1-1.5 times higher than the conventional duralumin alloys. For this purpose, pure elemental powders of Al and Cu were blended and milled in a planetary ball mill and sintered at 550°C for 1 hour in Argon atmosphere. XRD and SEM of samples collected at different stages during milling and after sintering were done to determine the phase evolution and microstructural morphology of the current alloys. The crystallite size, lattice strain and lattice parameters were analyzed by Williamson-Hall method. The crystallite size decreases rapidly up to 7 hours of milling and becomes almost constant with further milling. Addition of SiC (5 and 10 vol. %) and TiO2 (5 and 10 vol. %) as reinforcements in the matrix improves the hardness. Addition of SiC reinforcement leads to better dispersion than TiO2 as evident from the hardness values. This is due to the higher modulus of elasticity of SiC which is almost double than that of TiO2.

Determining the flow characteristics of synthetic slag and optimizing the slag characteristics

Agarwal, Anup and Saha, Sudhir (2012) Determining the flow characteristics of synthetic
slag and optimizing the slag characteristics. BTech thesis.

PDF 1291Kb

Abstract

In the dynamics of blast furnace slag plays an important role in the quality of the hot metal produces and also the efficiency of the blast furnace. The quality of the hot metal depends on the formation and other mineralogical transformation that the slag undergoes during the passage of the burden. The minerals such as SiO2 and Al2O3 increases the viscosity of the slag whereas, CaO decreases the viscosity of the slag.The cohesive zone determines gas flow pattern. The cohesive zone's thickness is determined by the melting zone of the slag. The ore is compacted due to softening and melting in the cohesive zone. Minimizing the size, lowering the level of the cohesive zone, increases the efficiency of the blast furnace, improves productivity and decreases coke rate. The work is designed at arriving at a slag composition through actual experiments which will ensure the lowering of the cohesive zone of the blast furnace with simultaneous decrease in the difference between the softening temperature (ST) and flow temperature (FT) of the slag.Synthetic slags were formed by imitation of blast furnace slag using the major oxides (CaO, MgO, SiO2 and Al2O3) and disregarding the minor oxides. The mineralogical compositions of the slag can be varied to obtain different synthetic slag and thus the flow characteristics of the slag can be experimented for different synthetic Slags.