Effect Of Multidirectional Forging Research Articles

Effect of Multidirectional Forging on the Microstructures and Mechanical Properties of the Al–Mg–Si Alloy

Effect of Multidirectional Forging on the Microstructures and Mechanical Properties of the Al–Mg–Si Alloy

The Effect of Multidirectional Forging on the Microstructure and Superplasticity of the Al–Mg–Si–Cu System Alloys with Different Contents of Mg and Si

The Effect of Multidirectional Forging on the Microstructure and Superplasticity of the Al–Mg–Si–Cu System Alloys with Different Contents of Mg and Si

Effect of Multidirectional Forging and SIMA Process on Mechanical and Tribological Behavior of Hypereutectic Al-18 Wt.% Si Alloy

Effect of Multidirectional Forging and SIMA Process on Mechanical and Tribological Behavior of Hypereutectic Al-18 Wt.% Si Alloy

Effect of Multidirectional Forging on Microstructure and Properties of AZ40 Alloy

AZ40 alloy was operated with the plastic deformation by multidirectional forging (MDF). The evolution rules of microstructure and texture during forging were analyzed by means of metallographic microscope and electron backscattering diffraction (EBSD), and the evolution mechanism of texture during forging is explored. The results show that, with the increase of passes of forging, the strength of the basal texture decreases. After four passes of forging, the original {0001} basal texture is changed to {101̄0} and {21̄1̄0} cylindrical texture, and the Schmind factor of the alloy reaches the maximum. Through multidirectional forging, the anisotropy of the alloy is weakened, and the mechanical properties of each texture are improved compared with that of the extruded state. After four passes of forging, the plasticity of the alloy is the best and the elongation ratio reaches the maximum, which is 32.0%, 29.2% and 27.0%, respectively.

Effect of multi-directional forging and ageing on fracture toughness of Al–Zn–Mg–Cu alloys

Strength, ductility and fracture toughness are the most important mechanical properties of engineering materials. In this work, an Al–Zn–Mg–Cu alloy was subjected to multi-directional forging (MF) and ageing treatment. Microstructural evolution was studied by optical and electron microscopy and strength, ductility and fracture toughness were researched. After MF, the dislocation density was increased and the microstructure was refined. The strength and fracture toughness were increased, while the ductility was decreased sharply. Without compromising the strength, the ductility was improved significantly after ageing. The fracture toughness was increased further. The coarse and discontinuously distributed grain boundary precipitates were found to be responsible for higher fracture toughness of the fine-grained structure Al–Zn–Mg–Cu alloy.

The Effect of Multidirectional Forging on the Deformation and Microstructure of the Al–Mg Alloy

The effect of multidirectional forging on the evolution of the grain structure and the parameters of secondary-phase particles in the aluminum–magnesium alloy (Russian grade 1565ch) has been investigated using scanning and transmission electron microscopy. The multidirectional forging was performed at 200, 350, and 500°C to a total strain of 12. Five multidirectional forging cycles (cumulative strain ∑e = 12) at 350°C lead to fragmentation of particles of crystallization origin, reduce the average particle size of manganese dispersoids by half, and the average grain size by two orders of magnitude from 200 to 1–2 µm. The ultrafine-grained structure forms in 90% of the sample volume.

Effect of Multidirectional Forging and Subsequent Annealing to the Microstructure of Al-Mg-Mn Type Alloy

The grain refinement is important to improve both service properties at room temperature and superplasticity at elevated temperatures. This study focuses on the effect of multidirectional forging in isothermal conditions on the microstructure of Al-Mg-Mn-type alloy. The evolution of dislocation and grain structure, and precipitates of Mn-rich phase during multidirectional forging in a temperature range of 200 to 500 °C was studied. Multidirectional forging at temperatures of 200 and 300 °C leads to the formation of shear bands in the deformed grains. The multidirectional forging at 400 and 500 °C leads to the formation of a bimodal grain structure with fine- and coarse-grained areas. Subsequent recrystallization annealing at 500 °C increases the grain size and decreases the fine grains fraction in the samples pre-deformed at 400-500°C, and, on the contrary, annealing leads to formation homogeneous and fine grain structure with size up to 6.5 μm in samples pre-deformed at 200 and 300 °C.

Effect of Multidirectional Forging on the Microstructure and Mechanical Properties of the Al–Mg–Mn–Cr Alloy

The effect of multidirectional forging on the grain structure and parameters of secondary-phase particles in the Al–4.8Mg–1.2Mn–0.1Cr alloy has been investigated using the methods of the scanning and transmission electron microscopy. The multidirectional forging performed at a temperature of 350°C to a cumulative strain of 10.5 has resulted in a 1.5 decrease in average particle sizes of the manganese-bearing phases of crystallization origin and dispersoids and in the formation of a structure with a mean grain size of 1.7 µm. Multidirectional forging included in a sheet processing, in contrast to hot rolling, forms an equiaxed grain structure with a grain size of about 6 µm in recrystallized sheets and with enhanced strength characteristics.

Structure and Mechanical Properties of the Aluminum Alloy 1570C after Multidirectional Forging with Decreasing Temperature and Subsequent Rolling

The effect of multidirectional forging (MDF) with decreasing temperature and subsequent warm and cold rolling on the structure and mechanical behavior of the alloy 1570C (Al-5Mg-0.18Mn-0.2Sc-0.02Zr (wt.%)) was studied. The first MDF step was carried out at a temperature of 325°C to a strain of about 12 and the second step at 250°C to the strain of about 6. Subsequent rolling was performed in isothermal conditions at the appropriate MDF temperatures, as well as at room temperature with reductions of about 80%. The best complex of service and technological properties, involving data on the parameters of strength, plasticity, superplasticity, was obtained in sheets rolled from high-temperature MDF billet. Despite the more significant grain refinement and unique strengthening, the MDF temperature decrease led to almost complete degradation of superplastic properties. The nature of the alloy behavior found was discussed in detail.

Investigation of dry sliding wear properties of multi-directional forged Mg–Zn alloys

Abstract Effect of multi-directional forging (MDF) on wear properties of Mg–Zn alloys (with 2, 4, and 6 wt% Zn) is investigated. Dry sliding wear test was performed using pin on disk machine on MDF processed and homogenized samples. Wear behavior of samples was analyzed at loads of 10 N and 20 N, with sliding distances of 2000 m and 4000 m, at a sliding velocity of 3 m/s. Microstructures of worn samples were observed under scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and x-ray diffraction (XRD) and the results were analyzed. Mechanical properties were evaluated using microhardness test. After 5 passes of MDF, the average grain size was found to be 30 ± 4 µm, 22 ± 3 µm, and 18 ± 3 µm, in Mg–2%Zn, Mg–4%Zn, and Mg–6%Zn alloys, respectively, with significant improvement in hardness in all cases. Wear resistance was improved after MDF processing, as well as, with increment in Zn content in Mg alloy. However, it decreased when the load and the sliding distance increased. Worn surface exhibited ploughing, delamination, plastic deformation, and wear debris along sliding direction, and abrasive wear was found to be the main mechanism.

Effect of Multi-Directional Forging on the Microstructure and Mechanical Properties of β-Solidifying TiAl Alloy.

This study systematically investigated the influence of multi-directional forging (MDF) on the microstructural evolution, hot deformation behavior, and tensile properties of a β-solidifying TiAl alloy. The initial lamellar microstructure of an as-cast alloy was remarkably refined and homogenized by three-step MDF. High temperatures and multi-pass deformations were conducive to the decomposition of lamellae. A crack-free billet was obtained through three-step MDF, with a deformation temperature of 1250 °C and a forging speed of 0.1 mm/s, indicating that MDF can be applied to β-solidifying TiAl alloys by the proper control of the alloy composition and process parameters. Microstructural observation showed that the billet mainly consists of fine and equiaxed γ grains and a small amount of β phase. The tensile properties of the multi-directional forged alloy were also significantly improved, due to microstructure refinement. The ultimate tensile strength (UTS) and elongation (δ) at room temperature were 689.4 MPa, and 0.83%, respectively. The alloy exhibits excellent ductility at 700 °C. When the temperature was increased to 700 °C, the UTS decreased to 556 MPa and δ increased to 5.98%, indicating that the alloy exhibits excellent ductility at 700 °C. As the temperature further increased to 750 °C, δ dramatically increased to 46.65%, indicating that the ductile-brittle transition temperature of the alloy is between 700 °C and 750 °C.

Effect of Multidirectional Forging on the Grain Structure and Mechanical Properties of the Al⁻Mg⁻Mn Alloy.

The effect of isothermal multidirectional forging (IMF) on the microstructure evolution of a conventional Al–Mg-based alloy was studied in the strain range of 1.5 to 6.0, and in the temperature range of 200 to 500 °C. A mean grain size in the near-surface layer decreased with increasing cumulative strain after IMF at 400 °C and 500 °C; the grain structure was inhomogeneous, and consisted of coarse and fine recrystallized grains. There was no evidence of recrystallization when the micro-shear bands were observed after IMF at 200 and 300 °C. Thermomechanical treatment, including IMF followed by 50% cold rolling and annealing at 450 °C for 30 min, produced a homogeneous equiaxed grain structure with a mean grain size of 5 µm. As a result, the fine-grained sheets exhibited a yield strength and an elongation to failure 30% higher than that of the sheets processed with simple thermomechanical treatment. The IMF technique can be successfully used to produce fine-grained materials with improved mechanical properties.

Effect of Multi Directional Forging on Impression Creep Behavior of Zn-24Al-2Cu Alloy

Multi directional forging (MDF) of Zn-24Al-2Cu alloy were carried at 100°C and 200°C with total equivalent strain of 0.6 and 1.2 respectively. The average grain size was reduced from 30 to 1 µm after MDF processing. Impression creep behavior of MDF processed samples was studied at 2 kg and 2.5 kg load with temperatures 30, 50, 100 and 150°C. Microstructural characterizations were carried out using optical microscope, transmission electron microscope and X-Ray diffractometer. Steady state creep rate values were recorded in the range of 1.2x10-5 to 5.2x10-7. The four phase transformation occurred in the structure after MDF process and during the impression creep test. Initial stress exponent (n) values are in the range of 2.5 to greater than 5. High values of ‘n’ showed due to the existence of threshold stress. The true activation energy values calculated are in the range of 22-129 kJ/mol. Changes in creep properties of MDF processed samples seem to be more sensitive to change in temperature compared to microstructural differences. Lattice diffusion controlled by dislocation climb is the dominant creep mechanism.

Effect of multi-directional forging and annealing on abrasive wear behavior in a medium carbon low alloy steel

Abstract A medium carbon low alloy steel was processed by multi-directional forging (MF) and annealing. Microstructural evolution is studied by optical and electron microscopy and abrasive wear resistance is researched. After MF, the microstructure was refined. The tensile strength and hardness increased obviously, while the ductility decreased sharply. MF resulted in the improvement of abrasive wear resistance. Without compromising the tensile strength and hardness much, the ductility was improved significantly after subsequent controlled annealing. Higher ductility led to abrasive wear resistance for further improvement. Higher hardness, ductility and work hardening degree were found to be responsible for higher abrasive wear resistance of ultrafine-grained (UFG) medium carbon low alloy steel.

Multidirectional Forging of High-Leaded Tin Bronze: Effect on Wear Performance

The dry sliding wear behavior of high-leaded tin bronze alloy was analyzed after multidirectional forging (MDF). The effect of MDF on the wear performance was analyzed under various loads, sliding velocities, and sliding distances. X-ray diffraction (XRD) analysis and energy-dispersive X-ray spectroscopy (EDS) were carried out on wear surfaces to define the wear mechanism, and field-emission scanning electron microscopy to observe microstructures. The change in the dislocation density on the wear track was also measured using XRD peak broadening analysis. MDF alloys showed higher wear resistance than as-received (AR) alloy. The major factors responsible for the improved wear resistance were (a) improved mechanical strength due to decreased crystalline size, and (b) presence of high lead content in the alloy.

Effect of Multidirectional Forging and Heat Treatment on Mechanical Properties of In Situ ZrB2p/6061Al Composites

AbstractAluminum matrix composites that were reinforced by in situ zirconium diboride nanoparticles were fabricated from an aluminum-potassium tetrafluoroborate-potassium hexafluorozirconate system via a direct-melt reaction. The morphologies of the in situ particles and the mechanical properties of the composite were investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffractometry, optical microscopy and tensile tests. X-ray diffractometry and energy-dispersive X-ray spectroscopy showed the existence of zirconium diboride in the composite. Multidirectional forging and heat treatment were used to determine the effect of plastic deformation and heat treatment for the highest tensile strength applied to the composite. Multidirectional forging and heat treatment have a positive influence on the composite microstructure and tensile strength, which increase by 21.81 % and 13.43 %, respectively. The mechanism of multidirectional forging and heat treatment that affects the composite mechanical properties has been discussed. The heat-treatment parameters that affect the tensile strength include the solution-treatment temperature, aging temperature and aging time. The highest tensile strength with moderate extensibility loss was achieved for a specimen that was solution treated for 4 h at 793 K and with aging at 423 K for 4 h.

Effect of Multi Directional Forging on the Microstructure and Mechanical Properties of Zn-24 wt% Al-2 wt% Cu Alloy

Multi directional forging is an important process for producing fine grains in bulk materials by means of severe plastic deformation. Zn-Al alloy is used for making sleeves of plain bearings, but the presence of porosity degrades its usage in industrial application. In the present investigation, multi directional forging of Zn-24Al-2Cu alloy was carried out at 100 and 200 °C up to total strain of 0.6 and 1.2 respectively. Mechanical properties and microstructural characterization were carried out on the processed material. It was inferred that processing at 100 °C up to three passes increased ultimate tensile strength from 185 to 267 MPa with ductility of 14 %. The average grain size was reduced from 30 to 2 µm. In the case of samples processed at 200 °C up to six passes, the average grain size was reduced to 1 µm. The ultimate tensile strength increased to 276 MPa and ductility significantly improved to 21 %. The strength of the processed material increased due to strain hardening and grain refinement. Uniform distribution of various dispersed phases contributed to the enhancement of ductility during multi directional forging at 200 °C. Analysis of the fractured surface of the tensile samples revealed highly ductile nature of the fracture.

Effect of multidirectional forging and equal channel angular pressing on ultrafine grain formation in a Cu- Cr-Zr alloy

The microstructure evolution was investigated in a Cu-0.3%Cr-0.5%Zr alloy subjected to large plastic deformation at temperature of 400 °C. Two methods of large plastic deformation, i.e., equal channel angular pressing (ECAP) and multidirectional forging (MDF) were used. The large plastic deformations resulted in the development of new ultrafine grains. The formation of new ultrafine grains occurred as a result of continuous reaction, i.e., progressive increase in the misorientations of deformation subboundaries. The faster kinetics of microstructure evolution was observed during MDF as compared to ECAP. The MDF to a total strain of 4 resulted in the formation of uniform ultrafine grained structure, while ECAP to the same strain led to the heterogeneous microstructure consisting of new ultrafine grains and coarse remnants of original grains. Corresponding area fractions of ultrafine grains comprised 0.23 and 0.59 in the samples subjected to ECAP and MDF, respectively.

Effect of multidirectional forging on microstructures and tensile properties of a particulate reinforced magnesium matrix composite

Abstract A particulate reinforced magnesium matrix composite prepared with stir casting was subjected to multidirectional forging (MDF). The results showed that after 1 MDF pass the grain size of matrix in the composites decreased compared with as-cast composite, and increased with increasing the MDF temperature from 370 °C to 450 °C. With increasing the MDF passes at 370 °C, the particle distribution of the composite was improved until 3 MDF passes while the grain size of matrix in the composite reached a minimum after 4 MDF passes. Both the yield strength and the ultimate tensile strength of the composite were enhanced with increasing the MDF passes.

Effect of Pass Strain on Grain Refinement in 7475 Al Alloy during Hot Multidirectional Forging

Effect of pass strain (� ) on grain refinement was studied in multidirectional forging (MDF) of a coarse-grained 7475 Al alloy at 490 C under a strain rate of 3 10 4 s 1 . Samples of rectangular shape were deformed up to accumulated strains of around 6 with subsequent changes in loading direction 90 from pass to pass. The pass strains in each compression (� ) were 0.4 and 0.7. The cumulative flow curves integrated by each compression exhibit significant work softening just after yielding, followed by apparent steady state plastic flow at high strains. Structural changes were characterized by grain fragmentation due to frequent development of deformation and/or microshear bands followed by full evolution of new fine grains in the original grains. Increasing � accelerates significantly the kinetics of grain refinement, leading to more clear reduction of flow stresses at moderate to high strains. MDF of � ¼ 0:7 results finally in formation of a finer grained structure with an average size of around 7.5 mm at strains of above 3.5, while, the processing with � ¼ 0:4 develops a slightly coarser grain structure at higher strain of about 6. The effect of MDF on new grain evolution and the mechanisms of grain refinement are discussed in details.