Influence of process parameters of aluminothermic reduction process on grain refinement of in-situ Al/ TiB2 composites

AbstractThis paper reports the influence of process parameters on the size and distribution of in situ titanium diboride (TiB2) particles within the aluminium (Al) matrix. TiB2 particles were formed as a result of the in situ reaction of potassium hexafluorotitanate (K2TiF6) and potassium tetra fluoroborate (KBF4) with molten Al. Two process parameters, namely, the addition time (AT) and holding time (HT) of precursor salts, were considered. The Al/TiB2 composites were produced by allowing the in situ reaction to occur at various ATs (10, 20, and 30 min) and HTs (20, 30, and 40 min). Results showed that the formation of TiB2 was confirmed by XRD analysis. The microstructure, TiB2 particle size, hardness, yield strength (YS), and ultimate tensile strength (UTS) were strongly affected by the said process parameters. The variations in hardness and UTS were highly consistent with those found in the microstructure of the composites. Compared with the Al parent material, the increase in the average hardness and UTS of the composite were 51% and 44%, respectively. This improvement was achieved for the composite sample fabricated with 20 min of AT and 30 min of HT. At this condition, the composite displayed near-uniform particle distribution.

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Influence of Process Parameters on Microstructure of Reaction Plasma Cladding TiC-Fe-Cr Coating

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1027.170 ◽

2021 ◽

Vol 1027 ◽

pp. 170-176

Author(s):

Li Mei Wang ◽

Jun Bo Liu ◽

Jun Hai Liu

Keyword(s):

Process Parameters ◽

Composite Powder ◽

Early Stage ◽

Influence Of Process Parameters ◽

Synthetic Process ◽

Plasma Cladding ◽

Cr Coating ◽

Composition Process ◽

Cladding Layers

In order to improve the quality and properties of the coating, a certain amount of Ti was added to the plasma cladding Fe-Cr-C coating in the early stage. And Fe-Cr-C-Ti composite powder was prepared by precursor carbonization-composition process. In situ synthesized TiC-Fe-Cr coatings were fabricated on substrate of Q235 steel by plasma cladding process with Fe-Cr-C-Ti composite powder. Microstructure of the coating with different process parameters, including cladding current, cladding speed, number of overlapping cladding layers, were analyzed by scanning electron microscope (SEM). The results show that the structure of the TiC-Fe-Cr coating is greatly affected by the fusion current, the cladding speed and the overlapping cladding process. In this test, when the cladding current of 300A and the cladding process parameter of the cladding speed of 50 mm/min are clad with three layers, a well-formed and well-structured TiC-Fe-Cr coating can be obtained. Which are the best synthetic process parameters in this test.

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Influence of Process Parameters on Microstructure of Friction Stir Processed Mg AZ31 Alloy

International Journal of Surface Engineering and Interdisciplinary Materials Science ◽

10.4018/ijseims.2014010103 ◽

2014 ◽

Vol 2 (1) ◽

pp. 47-58

Author(s):

G. Venkateswarlu ◽

M.J. Davidson ◽

G.R.N. Tagore ◽

P. Sammaiah

Keyword(s):

Plastic Deformation ◽

Grain Refinement ◽

Process Parameters ◽

Tilt Angle ◽

Friction Stir Processing ◽

Rotational Speed ◽

Traverse Speed ◽

Homogeneous Microstructure ◽

Influence Of Process Parameters ◽

Friction Stir

Friction stir processing (FSP) has been developed on the principles of friction stir welding (FSW) as an effective and efficien new method for grain refinement and microstructural modification, providing intense plastic deformation as well as higher strain rates than other conventional severe plastic deformation methods. FSP produces an equiaxed homogeneous microstructure consisting of fine grains, resulting in the enhancement of the properties of the material at room temperature. The objective of the present paper is to examine the influence of friction stir processing (FSP) parameters namely tool rotational speed (RS), tool traverse speed (TS) and tool tilt angle (TA) on the microstructures of friction stir processed AZ31B-O magnesium alloy. This investigation has focused on the microstructural changes occurred in the dynamically recrystallised nugget zone/ stir zone and the thermo mechanically affected zone during FSP. The results presented in this work indicate that all the three FSP process parameters have a significant effect on the resulting microstructure and also found that the rotational speed has greatly influenced the homogenization of the material. The grain refinement is higher at intermediate rotational speed (1150 rpm), traverse speed (32 mm / min and tilt angle (10). It is established that FSP can be a good grain refinement method for improving the properties of the material.

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