Effect Of Cryogenic Treatment Research Articles

The effects of cryogenic treatment and impact-oscillatory loading on changes in the mechanical properties and structural condition of stainless steel 12Kh18N10T

Research findings are presented dealing with the combined effect of cryogenic treatment + impact-oscillatory loading applied in different sequences on changes in the mechanical properties of stainless steel 12Kh18N10T. One-hour long cryogenic treatment and impact-oscillatory loading (IOL) applied at room temperature were shown to be practically unable to change the mechanical properties of the steel. At the same time, IOL pre-applied at a temperature of liquid nitrogen followed by static tensioning at room temperature proved to cause significant changes in the mechanical properties of the steel. Under further static tensioning, when IOL εimp = 2.7...12.5% (assigned intensity range of introducing impulse energy into steel) or, more specifically, when εimp = 9.69%, the ultimate strength of the steel was found to reach its maximum value, increasing by 32,2% compared to baseline, while ductility decreased by 26%. Specific physical investigations using the TEM microscope were conducted. The analysis of the steel structure of a specimen pre-subjected to IOL in liquid nitrogen at εimp = 9.63% indicates that under such complex loading conditions the well-known mechanism of plastic deformation by sliding changes into plastic deformation by twinning upon further static tensioning, and the strength of the steel increases.

Effect of cryogenic duration on the tribological properties of sintered polycrystalline c-BN during sliding mating materials in vacuum

The service performance of polycrystalline cubic boron nitride (PcBN) tools undergoes significant changes due to the deep space environment to the structure and wear behaviors of PcBN. In this paper, the effect of cryogenic treatment (CT) was studied to investigate the physical and tribological behaviors of PcBN. The hardness and wear resistance of PcBN are improved but wear forms are not affected, which are abrasive wear. The shedding of cBN played the role of micro-cutting edges, carving furrows on surfaces. As the CT duration increases, the wear rate of PcBN decreases from 2.56 × 10−8 mm3/N mm to 1.61 × 10−8 mm3/N mm for sliding against Si3N4. When PcBN slid Al2O3, the lowest wear rate is 1 × 10−8 mm3/N mm which the decline reached 34 %. Due to discrepancies in physical and mechanical properties, Si3N4 and YG8 balls exhibit abrasive and adhesive wear, and Al2O3 shows fatigue wear. Until the fatigue failure appeared, Al2O3 exhibited the lowest wear rate of 2.30 × 10−9 mm3/N mm. Among three materials, the wear rate of Si3N4 was the highest. By calculating the wear rate ratio of the materials, it was concluded that the optimal removal efficiency was achieved for Si3N4 and YG8 when CT duration is 24 and 48 h, respectively.

On the Effects of Deep Cryogenic Treatment on Wear Resistance, Hardness and Microstructure of the AISI D2 and D3 Tool Steel

The present study investigates the effect of cryogenic treatment on AISI D2 and D3 tool steels. This analysis is carried out for several heat treatment cycles that follow various tempering and cryoprocessing sequences that are not analysed erstwhile. Moreover, the effect of these heat treatment cycles on wear characteristics, hardness, and microstructural features of AISI D2 and D3 tool steel is also analysed. It is demonstrated that the cryogenic treatment significantly improves the wear resistance, hardness, and retained austenitic transformation of both types of material specimens under consideration. Furthermore, it is established that single tempering after cryogenic treatment is more effective than double tempering processes carried out in different sequences. It is also revealed that the double tempering sequencing involving cryoprocessing stalls the transformation of retained austenite, leading to higher wear and low hardness in the material

Effect of Cryogenic Treatments on Hardness, Fracture Toughness, and Wear Properties of Vanadis 6 Tool Steel.

The ability of cryogenic treatment to improve tool steel performance is well established; however, the selection of optimal heat treatment is pivotal for cost reduction and extended tool life. This investigation delves into the influence of distinct cryogenic and tempering treatments on the hardness, fracture toughness, and tribological properties of Vanadis 6 tool steel. Emphasis was given to comprehending wear mechanisms, wear mode identification, volume loss estimation, and detailed characterization of worn surfaces through scanning electron microscopy coupled with energy dispersive spectroscopy and confocal microscopy. The findings reveal an 8-9% increase and a 3% decrease in hardness with cryogenic treatment compared to conventional treatment when tempered at 170 °C and 530 °C, respectively. Cryotreated specimens exhibit an average of 15% improved fracture toughness after tempering at 530 °C compared to conventional treatment. Notably, cryogenic treatment at -140 °C emerges as the optimum temperature for enhanced wear performance in both low- and high-temperature tempering scenarios. The identified wear mechanisms range from tribo-oxidative at lower contacting conditions to severe delaminative wear at intense contacting conditions. These results align with microstructural features, emphasizing the optimal combination of reduced retained austenite and the highest carbide population density observed in -140 °C cryogenically treated steel.

An Investigation into the Effect of Length Scale of Reinforcement on the Cryogenic Response of a Mg/2wt.%CeO2 Composite

The present study attempted for the first time an investigation on the effect of deep cryogenic treatment in liquid nitrogen (LN) on magnesium–cerium oxide (Mg/2wt.%CeO2) composites containing equal amounts of different length scales (micron and nanosize) cerium oxide (CeO2) particles. The disintegrated melt deposition method was used to synthesize Mg-2CeO2 micro- and nanocomposites, followed by hot extrusion as the secondary processing. Further liquid nitrogen treatment was performed at a cryogenic temperature of −196 °C. The combined effects of cryogenic treatment and reinforcement length scale on physical, mechanical, and thermal behaviors were studied. The results indicate that LN-treated micro- and nanocomposite samples exhibit, in common, a reduction in porosity, similar grain size, and a limited effect on the original texture of the matrix. However, microhardness, 0.2% Compressive Yield Strength (CYS), failure strain, and energy absorbed increased for both micro- and nanocomposite samples. Overall, results clearly indicate the capability of deep cryogenic treatment with LN to positively diversify the properties of both micro- and nanocomposite samples.

Experimental Study on Effect of Cryogenic Treatment on Cutting Force of Titanium Alloy

Three titanium alloy materials TA7, TB6 and TC4 were selected, and three titanium alloys with different phases were placed in liquid nitrogen at -196°C for cryogenic treatment, and the change of the cutting performance of titanium alloy samples before and after cryogenic treatment was studied.Six speed combinations of 30m/min, 40m/min, 50m/min, 60m/min, 70m/min and 80m/min were selected to carry out cutting tests.The cutting experiments show that the cutting performance of TA7, TB6 and TC4 titanium alloys has been significantly improved by cryogenic treatment.At different cutting speeds, the cutting force was compared. After cryogenic treatment of three titanium alloy materials, the cutting force was reduced in machining.After cryotreatment, the cutting performance of TB6 was significantly improved, while that of TA7 was relatively low. Among them, TB6 showed the greatest improvement, followed by TA7 and TC4.The three titanium alloys without cryogenic treatment have a cutting speed of 50m/min at maximum cutting force.The maximum cutting force speed of cryogenic titanium alloy is 40m/min.

Effect of Cryogenic Treatment on Tribological and Surface Properties of 3D Printed Thermoplastic Polyurethane

Effect of Cryogenic Treatment on Tribological and Surface Properties of 3D Printed Thermoplastic Polyurethane

Implications of cryogenic treatment on microstructure, phase formation, mechanical and tribological properties of tungsten carbide cutting bits with varying cobalt content for mining applications

This study aims to provide a comprehensive analysis on the effect of cryogenic treatment on two different grades of WC rock cutting bits (low cobalt grade: WC-9 wt% Co and high cobalt grade: WC-25 wt% Co). The cutting bits are exposed to cryogenic treatment at different holding time such as 12, 24 and 36 h. The treated and untreated bits are characterized for low temperature DSC, phase analysis, microstructural study, elemental composition, hardness, fracture toughness and scratch test. Phase shift was observed for both the cases due to the martensitic phase transformation from α-Co (fcc) to ε Co (hcp) during cryogenic treatment. This transition was confirmed with low temperature DSC analysis between −90 °C and − 60 °C. New η carbide particles (Co6W6C) was formed for WC-25%Co and no such carbides was found for WC-9%Co. CT 36 of WC-25%Co exhibited a higher level of precipitation of η carbides. The results show that CT has enhanced hardness for both low (14.08%) and high cobalt (23.34%) WC cutting bits compared to untreated bits whereas density is not altered evidently. CT 24 and CT 36 possessed higher hardness and lower fracture toughness for WC-9%Co and WC-25%Co respectively. Higher CoF and formation of tribo layer was observed for treated bits whereas untreated bit experiences surface fracture and cracks as a result of scratch test. As a finding, mining sectors can utilize cutting bits that have undergone sustainable cryogenic treatment for rock cutting applications.

Microstructure evolution, phase formation, mechanical and tribological response of deep cryogenically treated hard WC-6%Co cutting bits

Improving the productiveness of rock cutting bit is an essential requirement for sustainable mining. Different heat treatment techniques are employed in the past to improve the proficiencies of cutting bits. Out of them, cryogenic treatment (CT) is accepted as a viable method for expanding the service life of a variety of cutting tool materials. The intention of the present study is to evaluate the effect of cryogenic treatment under varying soaking duration (12, 24 and 36 h) on hardness and wear resistance of WC-6%Co rock cutting bits. It also addresses the underlying mechanisms that CT carries in the modifications of microstructure and phase transformation. The β-Co phase fraction has been significantly reduced due to cryogenic treatment. The wear resistance of both cryo-treated and untreated bits was examined by scratch test and sliding wear test. From the results, an increase in hardness (CT 24–13.09 %) was observed as compared to UT, which is associated with a transformation from face-centered cubic α-cobalt (FCC α-Co) to hexagonal close-packed ε-cobalt (HCP ε-Co) phase due to cryogenic treatment. The coefficient of friction and wear resistance for the cryo-treated bits correspondingly increases in comparison to the untreated bit. CT 24 bit exhibits the maximum hardness of 2212 HV, an elevated COF (16.64 %) and the highest wear resistance (87.15 %) compared to UT and other CT bits. From the results, cryogenic treatment of cutting bits can be recommended for rock cutting application in mining industries.

Cryogenic treatment: Processing segment to tailor the interface and improve mechanical performance of impact modified PET/PBT blends

Cryogenic treatment of polymers is a well-known area of research these days. Many reports confirm the fact that, similar to metals, polymeric materials also undergo some structural changes that ultimately enhance mechanical properties like wear performance, tensile strength, impact strength, elongation, hardness, etc. The cryogenic treatment has proven an advantage for improving the properties of both virgin polymers and polymer micro- and nanocomposites. The present study, the first of its kind, reports the effect of cryogenic treatment on polymeric blends. An attempt is made to explore the effect of the treatment parameters, like temperature and time, on the impact modified and unmodified PET/PBT blends. Similar to the polymers and composites, the blend systems studied here reflect significant improvement by ∼50% in wear performance, ∼16–19% in tensile strength, and ∼9% in impact strength after cryogenic treatment. Thus, after extensive analysis of the material properties, structure, and thermal behavior, cryogenic treatment of PET/PBT blends, both impact-modified and unmodified, is advocated as an effective tool for tailoring the interface and improving performance.

Enhancement of corrosion resistance of CrMoV low alloy steels using cryogenic treatment

The current investigation explores the effect of cryogenic treatment on the microstructural and corrosion behavior of CrMoV low-alloy steels. The casted samples in the required dimensions were treated by annealing followed by deep cryogenic treatment (DCT). Initially, the microstructural modification brought by combined treatments was studied using an optical microscope (OM), scanning electron microscope (SEM), and x-ray diffraction (XRD) technique. After DCT, a refined and uniform grain structure was identified. The DCT resulted in the development of a fine-grained structure and reduced the mean grain size of the alloy, and this refinement of the grain structure is due to the reduction of lattice defects during the cooling process. The corrosion behavior was studied using the weight loss and Tafel polarization tests. The corrosion findings indicated a significant enhancement in the corrosion resistance of the specimens after DCT. The DCT specimens exhibited higher corrosion potentials compared to the base material. The DCT can promote the development of a more protective passive layer on the sample’s surface. This passive layer serves as an obstacle, preventing the diffusion of corrosive products and increasing corrosion resistance. Finally, it suggests that DCT positively impacts the CrMoV steels’ resistance to corrosion.

A survey of the effect of cryogenic treatment and natural ageing on structural changes and second-phase precipitation in Al–Zn–Mg–Cu alloy

A survey of the effect of cryogenic treatment and natural ageing on structural changes and second-phase precipitation in Al–Zn–Mg–Cu alloy

Impact of cryogenic treatment on mechanical and electro active actuation properties of soft polymers

AbstractThe goal of this study is to investigate the change in stretchability property of soft polymers before and after cryogenic treatment. To achieve this, the influences of cryogenic treatment on the rate dependent tensile properties, hysteresis behavior, and stress‐relaxation of soft polymers are extensively analyzed. Results indicated that the effects of cryogenic treatment for both VHB and Ecoflex samples on mechanical responses were more prominent at low strain rate. It was also observed that VHB polymer could exhibit more strain rate sensitivity than Ecoflex sample after cryogenic treatment. For stress relaxation test, both cryo‐treated polymer samples were found to yield less overall stress and takes longer time to reach equilibrium stress in comparison to untreated polymer. Extensive experimental findings showed that the amount of energy dissipated while cooling below glass transition temperature (Tg), causes stress softening with lowering of viscoelastic property. On the other hand, there is a good enhancement of the electro‐active actuation strain for the cryo‐treated VHB 4910 and Ecoflex specimens. The results of this work could be used as a helpful guide for applying cryogenic treatment to improve electro‐mechanical properties of soft polymers, as the theory underlying this treatment has not been well explored

Effect of Cryogenic Treatment on the Properties of Low Carbon A858 Steel

This study is concerned with the effect of Deep Cryogenic Treatment (DCT) at liquid nitrogen temperature (-196 o C) on the mechanical properties and performance of low carbon steel (A858). The tests specimens were divided in to two groups, the first group was subjected to the conventional heat treatment of normalizing, and the second group was also normalized then subjected to (DCT). The results have shown that after (DCT), the Hardness, Tensile properties and the impact energy absorbed were all slightly increased. However the fatigue test showed some positive improvement in fatigue limit by 20(N/mm2 ), and the volume wear rates at different loads were significantly decreased after (DCT). The changes in microstructure due to (DCT) were clearly noticeable, the grain boundaries were no longer visible, and the Pearlite isles globalization was obvious.

Effect of holding time between cryogenic treatment and tempering process on microstructural and mechanical properties of Ti-6Al-4V alloy

This study investigated the effects of cryogenic treatment (CT) and tempering process on the mechanical properties of Ti-6Al-4V alloy. CT samples were exposed to atmosphere for various time intervals (0 h, 6 h, 24 h, 72 h) before tempering to explore the implication of temperature recovery time on overall mechanical performance. Results revealed a significant improvement in the hardness of CT samples compared to un-treated (UT). Interestingly, the hardness showed dependency on atmospheric exposure times of CT samples. The variation of Ti-6Al-4V phases generated during the cryogenic treatment was recovered as it was exposed to the atmosphere, and the degree of recovery was rather different depending on the exposure time. However, no notable differences in cross-sectional hardness and room temperature tensile properties were observed between the UT and CT samples. Hence, it was concluded that the CT only affected the surface hardness of Ti-6Al-4V alloy.

Synthesis and characterization of Pd doped MXene for hydrogen production from the hydrolysis of methylamine borane: Effect of cryogenic treatment

In this study, a palladium-doped cryo-MXene catalyst was prepared by a wet impregnation method and its catalytic activity was studied using the hydrolysis of methylamine-borane. The palladium nanoparticles were doped on the surface of the MXene substrate by chemical reduction of Pd+2 and characterized by different analysis techniques. The prepared palladium-doped MXene phases were cryogenically treated with liquid nitrogen at −160 °C. The morphological and structural characterization of particles was performed using a field emission scanning electron microscope, transmission electron microscope, and X-ray diffraction machine with Cu Kα radiation. The surface and bonding types of particles were determined by X-ray photoelectron spectroscopy. The palladium-doped cryo-MXene catalysts exhibited excellent catalytic performance in the hydrolysis of methylamine-borane with a turnover frequency (TOF) of 45.8 for 298 K. In addition, the palladium-doped cryo-MXene displayed good stability even after the five cycles.

Effect of cryogenic and electrolytic passivation treatment on wear resistance of M2 high-speed steel

Through cryogenic treatment and electrolytic passivation treatment of M2 high-speed steel (HSS), the effect of electrolytic passivation process parameters on the life of M2 HSS taps and the combined effect of cryogenic treatment and electrolytic passivation treatment on the wear resistance of the M2 HSS were investigated by using a scanning electron microscope (SEM) and energy-dispersive spectrometer (EDS). The results show that the life of M2 HSS tap after electrolytic passivation treatment increases most significantly under the theoretical edge radius; the functional relationship between the charge consumption (y) and the tap edge radius (x) is as follows: y = 8.135x − 48.842. The wear resistance of the sample after cryogenic and electrolytic passivation treatment is the highest, which is 1.52 times higher than those of the traditional heat treatment sample. This is due to the increase of the number of carbides on the surface of the specimens after cryogenic treatment; the distribution and size of carbides are relatively uniform; the average size of carbides is reduced by 60.4%. There is a carbon layer on the surface of the sample after passivation, which can effectively improve the wear condition. The size and number of carbides in the surface layer of the sample remain unchanged after passivation treatment, indicating that cryogenic treatment plays a key role in the performance of the material.

Effect of cryogenic treatment on B2 nanophase, dislocation and mechanical properties of Al1.4CrFe2Ni2 (BCC) high entropy alloy

In this paper, cryogenic treatment (at 77K) was first applied to solve the problem of strength and plasticity balance of body-centered cubic (BCC) type Al1.4CrFe2Ni2 high entropy alloy (HEA). The microstructure and mechanical properties of the HEAs after cryogenic treatment was studied systematically. The results show that cryogenic treatment has an intensive effect on the nanophases (B2), dislocations and mechanical properties. The nanophase is refined to 126.05 nm with cryogenic treatment for 24 h, which is 42.7% lower than the matrix alloy. The number of the nanophase is increased by 60%. With the increasing of cryogenic treatment time, the dislocation morphology evolves from short linear shape to long curved shape and ring shape in turn, and the dislocation density increases significantly. Al1.4CrFe2Ni2 HEA exhibits excellent mechanical properties (480 HV hardness and 3107 MPa fracture strength) after cryogenic treatment for 24 h, which increase 9.1% and 24.33% than the matrix alloy (440 HV and 2499 MPa) while maintain high fracture strain, up to 40.8%. This is attributed to the volume shrinkage and lattice distortion superposition of HEAs cause the extrusion effect between grains. Under the effect of cryogenic treatment, the internal stress increased with volume shrinkage and the dislocation strengthening obviously.

Evaluation of heat transfer in porous scaffolds under cryogenic treatment: a numerical study.

The present work had evaluated the effect of cryogenic treatment (233K) on the degradation of polymeric biomaterial using a numerical model. The study on effect of cryogenic temperature on mechanical properties of cell-seeded biomaterials is very limited. However, no study had reported material degradation evaluation. Different structures of silk-fibroin-poly-electrolyte complex (SFPEC) scaffolds had been designed by varying hole distance and hole diameter, with reference to existing literature. The size of scaffolds were maintained at 5 [Formula: see text] 5 mm2. Current study evaluates the effect of cryogenic temperature on mechanical properties (corelated to degradation) of scaffold. Six parameters related to scaffold degradation: heat transfer, deformation gradient, stress, strain, strain tensor, and displacement gradient were analyzed for three different cooling rates (- 5K/min, - 2K/min, and - 1K/min). Scaffold degradation had been evaluated in the presence of water and four different concentrations of cryoprotectant solution. Heat distribution at various points (points_base, point_wall and point_core) on the region of interest (ROI) was found similar for different cooling rates of the system. Thermal stress was found developing proportional to cooling rate, which leads to minimal variation in thermal stress over time. Strain tensor was found gradually decreasing due to attenuating response of deformation gradient. In addition to that, dipping down of cryogenic temperature had prohibited the movement of molecules in the crystalline structure which had restricting the displacement gradient. It was found that uniform distribution of desired heat at different cooling rates has the ability to minimize the responses of other scaffold degradation parameters. It was found that the rates of change in stress, strain, and strain tensor were minimal at different concentrations of cryoprotectant. The present study had predicted the degradation behavior of PEC scaffold under cryogenic temperature on the basis of explicit mechanical properties.

Effects of Cryogenic Treatment on the Microstructure, Hardness, and Wear Behavior of 1.2436 Steel

Effects of Cryogenic Treatment on the Microstructure, Hardness, and Wear Behavior of 1.2436 Steel