Plastic Deformation Technology Research Articles

Research on incremental forming simulation based on an improved constitutive model

The incremental sheet metal forming process, characterized by the step-by-step deformation of sheet metal using a simple die, is classified as a type of plastic deformation technology. This method allows for the formation of complex-shaped parts even without the use of a specialized die. Its notable characteristic lies in its low forming load and high flexibility. To accurately forecast finite element simulation outcomes for the incremental sheet forming of 2024-O aluminum alloy sheets, constructing a precise constitutive model is essential. Typically, the uniform strain range in traditional unidirectional tensile tests does not surpass 0.3, primarily due to the necking phenomenon. This limitation hampers the accurate prediction of the actual large plastic deformation process. To address this issue, a theoretical model describing the stress-strain relationship in metal plastic deformation processes is developed using crystal plasticity theory. The constitutive model for the forming of 2024-O aluminum alloy is then constructed by adjusting the hardening coefficient and hardening index. Utilizing the improved constitutive model, the incremental sheet forming process is simulated using ABAQUS software. Upon comparison with experimental results, it is observed that the Thickness Average Absolute Relative Errors (TAARE) of the adjusted constitutive model at forming angles of 60°, 55°, and 50° are 0.414%, 0.467%, and 0.256%, and The Thickness Root Mean Square Errors (TRMSE) are determined as 0.0121, 0.0116, and 0.0094, respectively. These results indicate that the constitutive model and parameters established in this study can adequately capture the mechanical behavior of 2024-O aluminum alloy during the incremental sheet forming process.

Microstructural evolution in laser-based directed energy deposition of 316 L stainless steel with interlayer deformation

There has been a significant industrial interest in additive manufacturing (AM) technologies such as directed energy deposition (DED) due to their ability to produce complex geometries with controlled microstructures. More recently, AM processes have been hybridized with plastic deformation technologies to achieve further benefits. In this experimental work, we systematically investigate the microstructural evolution in a DED process, selectively coupled with interlayer deformation using 316 L stainless steel. Our results revealed that the region below the interlayer deformed surface comprised of a recrystallized zone and a retained deformation zone with increased hardness in both zones. The region above the interlayer deformed surface experienced a refined solidification at both the grain and the sub-grain levels, which was attributed to the change in nucleation conditions due to the interlayer deformation. Moreover, microstructural evolution was found to vary significantly under different deformation levels and DED parameters. The extent of the recrystallized zone increased with increasing interlayer deformation level and decreased with faster scan speed. The findings provide comprehensive insights into the microstructural evolution in AM processes coupled with interlayer deformation and could pave the way for quick and cost-effective methods to engineer microstructures for different applications.

Model of surface plastic deformation technology without coolant application developed based on the use of the Ansys information system and experiment

In the modern engine industry, the rates of accuracy, reliability and efficiency are at quite high levels, so when it comes to improving performance within any category of parameters, in particular the timeframe for modernizing production or developing a new product or technology, engineers and scientists are now creating software that will use a digital twin technology both at the design and production stages to launch the project. This article demonstrates the research results of the digital twin development for the surface plastic deformation technology by smoothing without coolant, the tool material of hard alloy VK 8 and a workpiece of steel 40 X obtained by performing a real experiment on the Ramo lathe machine and calculated in the ANSYS software. The technologies developed will significantly reduce the lead time for manufacturing engine parts in the machine-engineering and airspace industries.

Research Progress of Aluminum Alloy Welding/Plastic Deformation Composite Forming Technology in Achieving High-Strength Joints.

Fusion welding causes joint deterioration when joining aluminum alloys, which limits the use of aluminum alloy components in high-end equipment. This paper focuses on an overview of how to achieve high-strength aluminum alloy welded joints using welding/plastic deformation composite forming technology. The current technology is summarized into two categories: plastic deformation welding and plastic deformation strengthening. Plastic deformation welding includes friction stir welding, friction welding, diffusion welding, superplastic solid-state welding, explosive welding, and electromagnetic pulse welding. Plastic deformation strengthening refers to the application of plastic deformation to the weld seam or heat-affected zone, or even the whole joint, after welding or during welding, including physical surface modification and large-scale plastic deformation technology. Important processing parameters of plastic deformation welding and their effects on weld quality are discussed, and the microstructure is described. The effect of plastic deformation strengthening technology on the microstructure and performance evolution, including the hardness, tensile strength, fatigue property, residual stress, and hot cracking of aluminum alloy welded joints, and its evolution mechanism are systematically analyzed. Finally, this paper discusses the future development of plastic deformation strengthening technology and anticipates growing interest in this research area.

Ascertaining the microstructural evolution and strengthening mechanisms of the gradient nanostructured pure titanium fabricated by ultrasonic surface rolling process

This work utilized the ultrasonic surface rolling process (USRP) to construct a gradient nanostructured (GNS) layer in pure titanium. The microstructural characterization at different depths was conducted using a transmission electron microscope (TEM) and electron backscatter diffraction (EBSD) to elucidate the grain refinement mechanisms. Results showed that the {10−12} extension twins (ETs) and {11−22} compression twins (CTs) and their intersections accommodate the strain at the early deformation stage. As the strain increased, the dense dislocation walls (DDWs) and dislocation cells (DCs) gradually evolved into laminated structures with low-angle grain boundaries (LAGBs). Compared to conventional severe plastic deformation (SPD) technology, the LAGB-dominated grain refinement mechanism delays the onset of the transformation process from LAGBs to high-angle grain boundaries (HAGBs). With the coaction of discontinuous dynamic recrystallization (dDRX) and amorphization, the grains are extremely refined to 11.7 nm. Tensile test results suggested that a considerable strength-ductility synergy is achieved. The enhanced strength was attributed to grain size, dislocation, and synergetic strengthening mechanisms, accounting for 55.5 %, 20.7 %, and 23.8 %, respectively. This work deepens the current understanding of the formation mechanism of the GNS layer in pure titanium processed by USRP and the relationship between microstructure and mechanical properties.

A mini-review of surface severe plastic deformation methods and their effects on steel and stainless steel

Surface severe plastic deformation is an important technology for the preparation of bulk ultrafine grain or even nanocrystalline materials. Based on the technical achievements made in the field of surface severe plastic deformation at home and abroad, this article presents the basic principles of various kinds of surface severe plastic deformation techniques in detail. In addition, the effects of surface severe plastic deformation on the microstructure and mechanical properties of steel and stainless steel are reported. The current status of research on the effects of surface severe plastic deformation on fatigue properties and the tribological and biological properties of steel and stainless steel are summarized. The problems of the current surface severe plastic deformation technology for steel and stainless steel are pointed out, and the future development trend is foreseen.

Высокопрочные фторопластовые композиты с повышенной сопротивляемостью к деформациям под нагрузкой

This paper presents the results of research on the development of technology for plastic deformation of polymer blanks based on polytetrafluoroethylene (PTFE) and carbon fibers of the UVIS-AK-P brand in order to increase their strength and creep resistance. The dependence of the physico-mechanical and tribotechnical characteristics of the obtained composites is investigated and compared with a composite of the same composition, but obtained using a previously developed technology. It is established that the use of plastic deformation technology for the properties of PCM based on PTFE and carbon fibers of the brand UVIS-AK-P is an effective solution for obtaining high-strength, wear-resistant composites, characterized by increased resistance to tensile loads. The developed composites obtained using plastic deformation are characterized by 3 times increased tensile strength and 22 – 29 times reduced creep compared to the original PTFE obtained by standard technology. Structural studies of the technology of plastic deformation of polymer blanks have shown that this technology leads to the orientation of the carbon fiber (CF) in the direction of the flow of the material and a change in the spiral conformation of macromolecules with a transition to a more stable conformation, which favorably affects its operational properties. The use of this method will make it possible to obtain high-strength polymer materials with increased resistance to deformation, promising for use for loading schemes with high tensile loads.

Microstructure evolution and mechanical properties of severely deformed TA15 alloy by multi‐directional forging and annealing

AbstractMulti‐directional forging technology, as a representative severe plastic deformation technology, is urgent to be developed because it has strong microstructure refinement and performance improvement effects. In this paper, multi‐directional forging experiments of TA15 titanium alloy with different passes were carried out at 700 °C using unrestricted multi‐directional forging die structure. Then the samples of TA15 titanium alloy after multi‐directional forging deformation were subjected to a high‐temperature vacuum annealing treatment. The test results reveal TA15 alloy was effectively refined through multi‐directional forging without any cracking with the increasing of deformation passes. The mechanism of grain refinement during multi‐directional forging included dynamic recrystallization, grain crushing and adiabatic shear deformation bands refinement. The amount and grain size of recrystallization grains increased when the annealing time increased from 1 hour to 4 hours. Supplemented by annealing, the adiabatic shear deformation bands microstructure with the mixed microstructure of coarse αp and fine αs were obtained and the hardness after multi‐directional forging and annealing was investigated. The yield strength and ultimate tensile strength increased by 26.1 % and 25.5 % respectively when the deformation pass increased to 3 passes compared with the initial specimen. The present work revealed that multi‐directional forging deformation combined with appropriate annealing could represent an efficient route to improve the microstructure and mechanical property of TA15 alloy.

Review of major technologies improving surface performances of Ti alloys for implant biomaterials

Ti alloys have many excellent properties, including low elastic modulus, desired corrosion resistance, nontoxicity, and biocompatibility. Hence, they promise to be major hard-tissue implant biomaterials (HTIBs). However, some properties, like surface hardness, wearability, and cellular activity, need to be enhanced. Moreover, their corrosion resistance in simulated body fluids and biocompatibility also need to be investigated systematically before practical applications. As HTIBs, the primary properties in clinical applications are wearability, corrosion resistance, and biocompatibility. Surface modification is a commonly used effective way to improve the above-mentioned disadvantages. This work is a brief review of the main surface modification technologies of Ti alloys for HTIBs (hereafter referred to as Ti alloys). The main surface modification technologies of Ti alloys are divided into four types, namely, physical technologies, chemical technologies, electrochemical technologies, and surface plastic deformation technologies. The principle and applications of these four types of surface modification technologies on Ti alloys are introduced one by one. Finally, the future directions for the surface modification of Ti alloys are proposed.

Surface modifications transform titanium alloys into biomaterials

Improvements to the metal, made via physical, chemical, electrochemical, and surface plastic deformation technologies, can overcome biocompatibility issues for hard-tissue implants

The Deformation Characteristics and Effect of Processing Parameters on the Microstructure of 7075 Al Shell Part Manufactured by Rotating Backward Extrusion

Rotating backward extrusion (RBE) is known as a new severe plastic deformation technology that effectively combines the features of conventional backward extrusion (CBE) and torsion deformation. In this study, 7075 Al alloy shell parts were successfully prepared by CBE and RBE with a different number of revolutions (N = 5, 10, 15, 25, 50) at 410 °C. The effects of the RBE process on the grain refinement, precipitates and properties of extruded parts were revealed, and the deformation characteristics were compared with CBE. The results showed that the RBE process could greatly eliminate the dead deformation zone at the bottom of the CBE section and significantly improved the comprehensive strain level of the material due to the addition of severe torsional deformation via an open punch. The grain refinement feature of RBE parts showed a gradient distribution that continuously weakened from the inner wall to the outer wall with decreasing compressive and torsional stress. Increasing the number of revolutions significantly promoted the level of grain refinement, the grain refinement range, and effectively broke down and refined the coarse insoluble Fe-rich phases of the extruded parts. It was revealed that the finest grain size of approximately 1.3 μm could be obtained in the inner wall region when N was increased to 25, which was linked to the comprehensive effects of continuous dynamic recrystallization and geometric dynamic recrystallization. RBE greatly promoted an improvement in properties of the extruded parts. After T6 treatment, the microhardness of the fine-grained region of the RBE (25 N) part increased to ~192–197 HV, compared with ~180 HV in the initial T6-extruded state.

Study of severe plastic deformations of metallic materials:- A move towards Amorphization

This review highlights one of the amorphization processes of metals, alloys as well as metal matrix composites (MMCs) and its benefits towards strength enhancements. The need for material properties such as low weight, improved strength, enhanced wear, and corrosion resistance along with sensible ductility instigated the researchers to investigate the effect of different reinforcements as well as processing techniques on light metals. Developments in different primary, as well as secondary processing techniques, partly resulted in the enhancement of material properties. Different severe plastic deformation (SPD) technologies consequence the formation of ultra-fine grain structures as well as even nano-crystalline materials hence resulting in alteration of material properties. The numerous techniques are high-pressure torsion (HPT), accumulative roll bonding (ARB), equal channel angular pressing (ECAP), repetitive corrugation and straightening (RCS), etc. The operational principles of different SPDs, microstructural revolutions, mechanical properties are reported here. Implementation of the SPD techniques for the property enhancement of aluminium matrix composites (AMC) is the limelight here. Furthermore, this article highlights the recent achievements and current developments in determining the deformation mechanisms.

Deformation temperature impact on microstructure and mechanical properties uniformity of GWZ932K alloy under reciprocating upsetting-extrusion

At present, there are great technical difficulties in achieving microstructure and mechanical properties uniformity in large-size billets prepared by severe plastic deformation technology. How to improve the process route to realize the microstructure and mechanical properties uniformity of the billets has become an urgent problem to be solved at present. In this paper, GWZ932K alloy is used for two reciprocating upsetting-extrusion (RUE) deformation methods with a cumulative strain of 5.38. The influence of isothermal temperature reciprocating upsetting-extrusion (IT-RUE) and decreasing temperature reciprocating upsetting-extrusion (DT-RUE) on the microstructure and mechanical properties uniformity of GWZ932K alloy is discussed in detail. The results show both IT-RUE and DT-RUE deformation methods can effectively refine grains. IT-RUE can prepare Mg alloy billet with uniform microstructure and mechanical properties from center region (CR) to edge region (ER). The microstructure and mechanical properties of the billet prepared by DT-RUE show obvious gradient characteristics from CR to ER. After 4 passes IT-RUE deformation, double-peak textures appear on the (0001) basal texture of the ER, middle region (1/2R) and CR, which is mainly attributed to the occurrence of dynamic recrystallization (DRX) behavior. It should be noted that changes in the deformation temperature will not cause changes in the DRX mechanism. The deformation mechanisms of continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) jointly promote grain refinement.

Truck Synchronizer Rings Recovery by Plastic Deformation Technology

A truck's gearbox friction rings restoring process by hot 3D stamping was developed and adopted for implementation. Using this recovery method in combination with subsequent synchronizer rings mechanical processing allows restoring up to 95% resource of worn parts. It was established that section of a stamp's deforming element for axisymmetrical parts restoring should be a one-way wedge with a sloping face facing the reconstructed surface. The most significant factors influencing the transmission gearbox synchronizer rings restoring process are: stamp deforming element thickness, plunging depth and distance to a recoverable surface. The energy and force parameters study of hot plastic deformation process serves as input data for automatic design systems of working elements of stamps for restoring synchronizer rings as well as for determination of a required deforming force during hot stamping.

Plastic deformation technology of high strength deformed magnesium alloy

The traditional plastic deformation technology of magnesium alloys is relatively poor at high temperature, so a plastic deformation technology of high strength wrought magnesium alloys is designed. Firstly, the slip surface and slip direction which affect the properties of magnesium alloy are analyzed, then the rolling finite element is simulated, the simulation results are visualized, and the simulation information required by the user is output. The results show that the temperature rise decreases with the increase of initial deformation temperature, the average grain size decreases and the uniformity of grain size distribution increases gradually due to dynamic recrystallization, and the cumulative strain and strain distribution in the strain field increases gradually with each pass due to the existence of shear stress in the stress field.

A review paper on magnesium alloy fabricated by severe plastic deformation technology and its effects over microstructural and mechanical properties

Abstract This review paper mainly focused on microstructural and mechanical properties ofultrafine grained nanocrystalline (Nc) Magnesium alloy fabricated by Severe Plastic Deformation(SPD) process. The influence of SPD over mechanical, microstructural, physical, optical, and corrosion properties of Nanocrystalline magnesium alloy are detailed and discussed. It has been observed that nanocrystalline (Nc) magnesium materials has shown superior properties over the bonding of grains while during the Extrusion, Annealing, quenching, Normalizing, Spark Plasma Sintering (SPS) processes. The outcome based by many researchers showed that nanocrystalline Magnesium alloy processed by Severe Plastic Deformation (SPD) showed an improved properties over the Hardness, Dislocation density, Compressive, Tensile and texture, and it’s found to be increased up to certain limit beyond that decrease of microstructural stability, micro hardness and dislocation density were seen to be observed. The Microstructural and Mechanical properties are well improved by Spark Plasma Sintering (SPS), Extrusion, Annealing, Equal channel angular pressing (ECAP), Accumulative Roll Bonding (ARB) and High-Pressure Torsion (HPT) processes. Grain growth Mechanism, Energies Activation during grain growth, Thermal stability, Relative density and stress corrosion rate were observed by previous Researchers during Fractography analysis over several nanocrystalline (Nc) Magnesium alloy specimens.

Microstructure and properties of LZ91 magnesium alloy processed by asynchronous accumulative roll bonding

In order to expand the application prospects of LZ91 magnesium alloy, improve its tensile strength and yield strength. In this paper, the asynchronous rolling and cumulative rolling technology are combined in the large plastic deformation technology, and the LZ91 magnesium alloy after coating the aluminum foil by the asynchronous accumulative roll bonding is performed. The analysis shows that the asynchronous accumulative roll bonding technology accumulates a large amount of deformation energy storage inside the material through large plastic deformation, and refines the grain to the micro-nano level, which increases the strength of the LZ91 magnesium alloy by 86% and the hardness by 63.97%. Improve the internal structure and application performance of the material.

Toward the development of Mg alloys with simultaneously improved strength and ductility by refining grain size via the deformation process

Magnesium (Mg) alloys, as the lightest metal engineering materials, have broad application prospects. However, the strength and ductility of traditional Mg alloys are still relativity low and difficult to improve simultaneously. Refining grain size via the deformation process based on the grain boundary strengthening and the transition of deformation mechanisms is one of the feasible strategies to prepare Mg alloys with high strength and high ductility. In this review, the effects of grain size on the strength and ductility of Mg alloys are summarized, and fine-grained Mg alloys with high strength and high ductility developed by various severe plastic deformation technologies and improved traditional deformation technologies are introduced. Although some achievements have been made, the effects of grain size on various Mg alloys are rarely discussed systematically and some key mechanisms are unclear or lack direct microscopic evidence. This review can be used as a reference for further development of high-performance fine-grained Mg alloys.

Contribution of ultrasonic surface rolling process to the fatigue properties of TB8 alloy with body-centered cubic structure

The effect of ultrasonic surface rolling process (USRP) as a severe plastic deformation technology was investigated on the evolution of microstructure, residual stress and surface morphology of TB8 alloys with body-centered cubic structure. Stress-controlled rotating-bending fatigue tests indicated increased fatigue strength in USRP samples prepared using different number of passes compared to the base material, which was attributed to the presence of gradient structure surface layers. Five subsequent USRP passes resulted in the highest fatigue strength, due to the optimal surface properties including higher extent of grain refinement, larger compressive residual stresses, “smoother” surface morphology and increased micro-hardness. However, the effect of USRP technology on improving fatigue strength of TB8 alloy was not significant in comparison with that of other titanium alloys (for example, Ti6Al4V), which was attributed to the notable surface residual stresses relaxation revealed from measurements on post-fatigued USRP samples. Electron backscatter diffraction analysis confirmed that fatigue crack initiation occurred in the larger grains on the surface with high Schmid factor. Small cracks were found to propagate into the core material in a mixed transgranular and intergranular mode. Further analysis indicated that grain growth existed in post-fatigued USRP-treated TB8 samples and that the average geometrically necessary dislocations value reduced after fatigue loading.

Study of structure of naturally aged aluminium after twist channel angular pressing

Twist channel angular pressing (TCAP), the severe plastic deformation (SPD) technology developed recently to increase the efficiency of the imposed strain and its homogeneity within a single pass, is an effective process combining channel bending and twist extrusion in a single die. The presented study analyses the phenomena of substructure development, precipitation, structural units' orientations, and the occurrence of residual stress, as well as electric resistivity and microhardness, in commercial purity aluminium naturally aged for two years at room temperature after processing via single pass TCAP. The results are compared with the findings for the TCAP sample right after processing; selected results are also compared with the results for the sample after TCAP and one year of natural ageing, and with a sample processed by conventional ECAP. The analyses showed the substructure to recover substantially, the grain size decreased to submicron size. The residual stress within the grains introduced by the energy accumulated via the severe imposed strain relaxed significantly by the structure restoration, as well as by intensive precipitation. The aged TCAP sample specific electric resistivity was comparable to the resistivity of the original commercially pure aluminium (2.652E-05 and 2.635E-05Ω·mm2·m−1, respectively), however, the microhardness mapping showed increased mechanical properties with homogeneous distribution.