Apparent Plastic Research Articles

Effect of SCM combinations on paste rheology and its relationship to particle characteristics of the mixture

Rheological properties of binary, ternary and quaternary combinations of ordinary Portland cement with Class F fly ash, slag, silica fume and metakaolin were evaluated with and without chemical admixtures. A linear relationship was observed between yield stress and BET specific surface area in the presence of chemical admixtures at a constant dosage for binary, ternary and quaternary combination of SCMs. Only binary combinations were examined without chemical admixtures where a linear relationship was observed between yield stress and packing density determined from normal consistency measurements. Although it is typically assumed that the effect of mineral admixtures on rheology is additive, it was observed in this study that combining SCMs did not have an additive effect on apparent yield stress and plastic viscosity, and consequently, these parameters for ternary and quaternary combinations cannot be estimated from their respective values for binary mixtures.

Thickening and rheological properties of slurries as functions of the oxidized nickel ore composition

The thickening and rheological properties of ore slurries and pulps after autoclave sulfuric acid leaching are analyzed as a function of the phase composition of oxidized nickel ore. Experiments have been carried out with samples of ferrous, silicate and combined ores. The initial concentration of the ore slurries is ∼28%. Higher values of thickening properties (thickening rate of 1.3 m/day, thickened layer concentration of 54%) are exhibited by the ferrous ore slurry and the pulp after its leaching (thickening rate of 0.9 m/day, thickened layer concentration of 42%). The thickening rate of silicate ore slurry is 0.15–0.2 m/day, the thickened layer concentration is 40–45%. The thickening properties of the pulp after autoclave sulfuric acid leaching of silicate ore strongly depend on the consumption of sulfuric acid. The thickening properties of combined ore and pulps after its leaching deteriorate with increase in the content of silicon dioxide in the ore. In terms of the rheological properties, all slurries are pseudoplastic systems. Poorly thickening slurries are characterized by a high dynamic yield stress (up to 7 Pa) and apparent plastic and effective viscosities. The effective viscosity at the equivalent shear rate corresponding to the mixer rotation rate in laboratory autoclave reaches 34 × 10–3 Pa s. Boundary values are determined in rheological constants with regard to the thickening properties. For instance, if the dynamic yield point is 1.0 Pa, the thickening rate decreases from 0.075 m/day to zero. The thickening and rheological properties are found to depend on the particle size of solid phase and its surface properties.

Effect of laser shock peening on the compressive deformation and plastic behavior of Zr-based bulk metallic glass

The compressive deformation and the plastic behavior of Zr35Ti30Cu8.25Be26.75 bulk metallic glass (BMG) in as-cast and laser peened state were investigated. It was found that as-cast sample displayed brittle fracture with an limited plastic strain of 0.22% and the fracture was mainly localized on one single shear band. For laser peened sample, an apparent plastic strain of 1.48% could be observed in the stress-strain curve, which was much greater than that of as-cast sample. Scanning electron microscope observations revealed that the normal fracture surfaces of both samples displayed a shear mode and consisted of vein-like structure. The relatively uniform distribution of multiple shear bands was observed on the side fracture surface of laser peened sample. Numerical simulation was performed to understand quantitatively the plasticity enhancement of laser peened sample. Under the effect of LSP induced residual stress, the laser peened sample exhibited a larger concentrated stress around the main shear stress plane which could promote the initiation of new shear bands. Besides, the increased free volume in main shear stress plane were beneficial for the generation of multiple shear bands which would probably improve the compressive plasticity of Zr-based BMG.

Micro‐Mechanical Behavior of an Exceptionally Strong Metal Matrix Nanocomposite Processed by High‐Pressure Torsion

This research describes the micro‐mechanical behavior of an Al–Mg alloy system synthesized from two separate commercial Al‐1050 and ZK60 alloys through the application of high‐pressure torsion (HPT) for five turns at room temperature. The essential mechanical characteristics of the alloys are observed at the corresponding phases in a multi‐layered structure at the disk center but the edge contains a metal matrix nanocomposite (MMNC) exhibiting an apparent plastic instability and decreasing strain rate sensitivity under strain rates of 10−4−10−3 s−1. The results demonstrate a significant opportunity for using HPT processing to prepare new alloy systems involving a wide range of MMNCs.

Enhancement of yield point at high pressure high temperature wells by using polymer nanocomposites based on ZnO & CaCO3 nanoparticles

Zinc oxide nanoparticles (ZnO-NPs) and modified calcium carbonate (nano-CaCO3) nanoparticles were successfully prepared and added to polystyrene-butadiene rubber copolymer (PSBR) matrix to prepare PSBR nanocomposites. The prepared nanomaterials (ZnO-NPs & nano-CaCO3) were characterized using scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Furthermore, the prepared polymer nanocomposites and oil base mud were used for drilling in high pressure high temperature (HPHT) wells. The consequence of using polymer nanocomposites based on different loading of ZnO-NPs and nano-CaCO3 on the rheological properties of oil base mud was evaluated and enhanced the yield point at high pressure high temperature wells (HPHT). The using of the polymer with different percentage from (0.5) in all percent the obtained results is very promising; this means that the increase of polymer is reasonable for the increase of apparent viscosity, plastic viscosity and yield point at high temperature. Correspondingly, polymer nanocomposites displayed rise of apparent viscosity, plastic viscosity, and yield point, decreased in fluid loss and increased in electrical stability at high pressure high temperature wells.

Discrete dislocation plasticity analysis of contact between deformable bodies of simple geometry

A contact mechanical model is presented where both metal bodies can deform by discrete dislocation plasticity. The model intends to improve on previous dislocation dynamics models of contact, where only a plastically deformable body was considered, flattened by a rigid platen. The effect of the rigid platen was mimicked through boundary conditions acting on the deformable body. While the formulation is general, the simulations presented here are only performed for contact between a plastically deforming body with sinusoidal surface and a flat body that is either elastic or rigid.Results show that the contact conditions, i.e. frictionless and full stick, affect the morphology of the contact as well as the contact pressure distribution. This is because dislocations can glide through the frictionless contact and fragment it, but do not penetrate a sticking contact. Average quantities like mean apparent contact pressure and total plastic slip are, instead, independent of contact conditions and of the details of the contact area.A size dependence is observed in relation to the onset of plastic deformation, where surfaces with smaller wavelength and amplitude require a larger contact pressure to yield than self similar surfaces with larger wavelength. The size dependence is very pronounced when the flat body is rigid, but fades when the compliance of the flat body is large.

Preparation and evaluation of cationic bolaform surfactants for water-based drilling fluids

Three cationic bolaform surfactants with different spacer lengths were prepared from the reaction of two moles of triisopropanolamine with one mole of each of the following 1,4-dibromobutane, 1,5-dibromopentane and 1,6-dibromohexane. The chemical structures of the prepared compounds were confirmed via: FTIR spectroscopy, 1H NMR and elemental microanalysis. The surface activity of these bolaform surfactants was studied. The prepared cationic bolaform surfactants were evaluated as viscosifier additives for water-based drilling fluids. The evaluation includes the study of rheological properties of the formulated mud (apparent viscosity, plastic viscosity and yield point, gel strength and thixotropy), effect of temperature on the rheological properties and also, the study of mineralogical properties of the water-based before and after treatment with the prepared surfactants using: X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results of the evaluation were compared to the water-based mud formulated from commercial grade bentonite.

A high-density organoclay-free oil base drilling fluid based on supramolecular chemistry

Abstract Based on supramolecular chemistry, a rheology modifier CFZTQ-1 for oil base drilling fluids was developed, and an innovative high-density organoclay-free oil base drilling fluid system centering on CFZTQ-1 was designed, evaluated and applied in the field. CFZTQ-1 can strongly increase the elasticity of invert emulsion due to the supramolecular structure assembled in water phase; CFZTQ-1 has stronger effect in elevating the yield point and suspension ability than several foreign rheology modifiers; the synergistic effect with organoclay also makes CFZTQ-1 available in traditional clay-contained invert emulsion drilling fluids. Through the category and dosage optimization of related additives, the formula of the high-density organoclay-free oil base drilling fluid was established and its performance was evaluated. The organoclay-free drilling fluid owns favorable rheology with density of 2.40−2.60 g/cm 3 , yield point of 13−17 Pa, moderate apparent viscosity and relative low plastic viscosity; after hot rolling at 240 °C, the drilling fluid still keeps a stable performance as its viscosity only increases slightly, its high temperature and high pressure (HTHP) filtration loss is about 10 mL and its electrical stability is greater than 400 V. This innovative drilling fluid system achieves excellent field application as well.

Bentonite-Free Water-Based Drilling Fluid with High-Temperature Tolerance for Protecting Deep Reservoirs

A bentonite-free water-based drilling fluid (BFDF) with high-temperature tolerance (up to 200°C) was developed for protecting reservoirs in deep wells. The fluid is composed of heatresistant polymeric thickener and starch, sodium sulfite, etc. A series of methods including environmental scanning electron microscopy (ESEM), linear expansion and hot-rolling dispersion test, and core-flow experiments and measurements of the rheological parameter, filtrate, and biotoxicity were used to evaluate the performance of the BFDF formulation. Laboratory results indicate that the fluid has excellent high-temperature tolerance. Its yield point and plastic viscosity ratio is up to 0.38 even after aging at 200°C for 16 h with API filtrate of 9.8 mL. Its apparent viscosity, plastic viscosity, and yield point at 180°C are 30 mPa·s, 17 mPa·s, and 14.5 Pa, respectively, which show its good well-cutting carrying performance and wellbore purification capacity. The BFDF formulation exhibits a strong ability to restrain the linear expansion rate of bentonite and shale powder, to improve cutting recovery, to protect the well reservoir by cutting down water blocking and lowering permeability damage, and to minimize biotoxicity with a high EC50 value and is suitable for drilling deep wells in environmentally sensitive areas.

Influência da massa molar de CMC no comportamento reológico e de filtração de suspensões argilosas

Resumo A carboximetilcelulose (CMC) é um polímero linear aniônico usado como agente viscosificante e redutor de filtrado e em fluidos de perfuração. A estrutura química e massa molar do polímero interferem nas interações complexas entre as cadeias poliméricas e os sólidos minerais presentes na suspensão. Desta forma, este trabalho teve como objetivo avaliar o comportamento reológico e de filtração de suspensões argilosas em função do aumento da concentração de aditivo polimérico com diferentes massas molares. Para tanto, foi utilizada uma amostra de argila bentonítica, comercialmente conhecida por Volclay, duas amostras de carboximetilcelulose com diferentes massas molares (CMC 1 (9,0 x 104 g/mol) e CMC 2 (2,5 x 105 g/mol)) e mesmo grau de substituição (DS = 0,7), e uma amostra de calcita. Foram determinadas as propriedades reológicas (viscosidades aparente e plástica, limite de escoamento e força gel) e de filtração (volume de filtrado, spurt loss ), espessura e permeabilidade do reboco, e poder de retenção) das suspensões argilosas. As propriedades reológicas e de filtração das suspensões argilosas preparadas com aditivos poliméricos são fortemente dependentes das interações CMC-argila e CMC-calcita e estas, por sua vez, são dependentes do grau de viscosidade e tamanho da cadeia do polímero.

Centimeter‐Sized Quaternary Ti‐Based Bulk Metallic Glasses with High Ti Content of 50 at%

Using copper mold suction casting, high Ti content alloys of Ti50Zr16Be24Ni10, Ti50Zr20Be20Ni10, and Ti55Zr15Be20Ni10 are fabricated in bulk metallic glasses (BMGs) with the critical diameters (Dc) of 10, 6, and 5 mm, respectively. In particular, the Ti50Zr16Be24Ni10 BMG is the first centimeter‐scale high Ti content BMG with Ti concentration as high as 50 at%. In addition, these high Ti content BMGs exhibit high specific strength and apparent plastic strain. Especially, the Ti50Zr16Be24Ni10 BMG exhibits a specific strength of 3.87 × 105 N m kg−1 and a plastic strain of 5.7 ± 0.5%. Our results indicate that a combination of lower Zr and higher Be contents promotes glass formation in the Ti–Zr–Be–Ni alloy system. The developed Ti‐based BMGs with high specific strength provide potentials for engineering applications.

Impact-induced bonding and boundary amorphization of TiN ceramic particles during room temperature vacuum cold spray deposition

Vacuum cold spray (VCS) has been developed as a competent technique for room temperature bulk coating fabrication of solid ceramic particles. Here we report formation and densification mechanisms of VCS TiN ceramic coatings as elucidated by characterizing their microstructures at particle/substrate and particle/particle interfaces. TEM observation reveals apparent fracturing and plastic deformation of TiN particles during impact deposition. The deformation located at the interfacial areas exhibits a dislocation density of ~5×1017/m2. Formation of an amorphous layer with the width of 3–4nm at the fringes of the ceramic particles is revealed. Impact velocity and high strain rate of TiN particles as determined by numerical computation further indicates the substantial role of the impact-induced plastic deformation in regulating the fabrication of the coatings. The results shed light on efficient room temperature bulk fabrication of ceramic materials with tunable structures.

Impact of Carob Pods Powder on the Physical and Sensory Properties of Ice Cream

The effects of carob pod fruit po􀀩der as a partial replacement of ice cream mi􀀪 SNF 􀀩ith levels of 8%, 􀀠6%and 24% on the physical and sensory properties of ice cream 􀀩ere evaluated. Specific gravity, 􀀩eight per gallon, pHvalues, freezing point and some rheological parameters of the prepared ice cream mi􀀪es, also the overrun, meltingresistance and sensory characteristics of the resultant ice cream 􀀩ere determined. Specific gravity, 􀀩eight per gallonand freezing point of ice cream mi􀀪es increased by replacement of SNF 􀀩ith carob pods po􀀩der. Also, the addition ofcarob pods fruit caused significant (p<􀀟.􀀟5) increase in apparent viscosity, plastic viscosity and consistency inde􀀪 alongthe aging period at 5±􀀠˚C for 24 hr. On contrary, overrun decreased significantly (p<􀀟.􀀟5) as replacement of SNFincreased. Moreover, the melting resistance (lo􀀩 melting ability) of carob ice cream sho􀀩ed a positive proportional(p<􀀟.􀀟5) 􀀩ith replacement levels of carob pods po􀀩der. Partially replacement of ice cream SNF 􀀩ith carob podspo􀀩der up to the level of 24% can be considered as carob flavoured ice cream 􀀩ith good physical and sensorycharacteristics.

Bentonite Clays Characterization in the Town of Sossego – Paraiba State

Bentonite exhibt a range of industrial applications moving millions of dollars on the market per year. Among several applications if highlights it is use for petroleum drilling fluids. Thus, this work aims to characterize physical, mineralogical and technologically, the bentonitics clays of Sossego County, Paraíba, Brazil. Mineralogical characterization of clays was done through the following techniques: particle size analysis by laser diffraction, thermogravimetric and differential thermal analysis, chemical analysis and x-ray diffraction. The clays were turned in by treatment with sodium in Na2CO3 and then determined whether the apparent viscosity, plastic and volume of filtrate of clay-water dispersions. The results showed that the samples are of polycationic, showing levels of MgO, CaO and K2O, similar to those from Boa Vista County, Paraíba, Brazil, and consist of clay mineral kaolinite, quartz and esmec. The clays showed rheological properties that indicate potential for use in drilling fluids.

Hardening and crystallization in monatomic metallic glass during elastic cycling

Abstract

Semi-solid Powder Rolling of AA7050 Alloy Strips: Densification and Deformation Behaviors

Semi-solid powder rolling (SSPR) is a novel strip manufacturing process which combines the features of semi-solid rolling and powder rolling. SSPR involves rolling procedure of metallic alloy powders when both liquid and solid phases coexist. In this study, densification process and deformation mechanisms of AA7050 powder in the presence of liquid phase were investigated. The relationships between the apparent plastic Poisson’s ratio and the relative density as well as the thickness reduction ratio and relative density were calculated. The relationship between deformation strain and relative density was calculated as well. The experimental data of relationship between rolling forces and relative density were achieved. The results show that the densification process of SSPR also can be divided into three stages and liquid phase mainly affects stage I. In stage I, semi-solid particles’ rearrangement and restacking are the main densification mechanisms when the initial liquid fraction is lower than 20 pct. When the initial liquid fraction is higher than 20 pct, flowing and filling of liquid, semi-solid particles rearrangement and restacking are the densification mechanisms. In stage II, severe deformation of particles associated with a rapid increase in the apparent plastic Poisson’s ratio and interparticle contact area contributes to the densification process. In stage III, the densification mechanisms are the deformation and collapse of isolated pores. The calculated deformation strain increases gradually with the same slopes as the relative density increases in stages II and III no matter how much the liquid fraction is. Higher liquid needs less deformation degree that contributes to the densification.

Enhanced Viscosity of Aqueous Palygorskite Suspensions through Physical and Chemical Processing

Palygorskite has remarkable rheological properties and was used to increase the stability and viscosity of aqueous suspensions. The effects of different physical and chemical processing methods on the apparent viscosity and plastic viscosity of the palygorskite suspensions such as pressing, ultrasound scattering, acidification, and chemical additives have been released. The pressing and ultrasound scattering indicated that the dispersed state of palygorskite could be increased effectively after treatment, and the apparent viscosity of treated-palygorskite samples increased almost 2-3 times compared to that of before. The viscosity of the acid-treated palygorskite suspension was not increased. The viscosity increased with the content of bentonite in the mixture of bentonite and palygorskite in fresh water. It seemed to be not worthy to add a certain amount of bentonite to palygorskite in order to enhance viscosity and vice versa. Chemical additives appeared to have good effects on the rheological behavior of palygorskite suspension. Magnesium oxide revealed great contribution to viscosity enhancement. The main mechanism was the electrostatic attractive interaction between magnesium oxide particles with positive charges and the palygorskite rods with negative charges. This interacted force has an impact on the structural inversion of palygorskite rods and even caused the reinforcing of flocculation.

Straining and relaxation properties of wet paper during heating

The influence of increasing temperature on the strength and relaxation of wet press-dry paper was studied using a tensile tester equipped with a special heating chamber. The heating chamber made fast heating possible without detectable moisture loss. The results showed that temperature had a significant influence on the straining, relaxation and re-straining behavior of wet paper. The majority of observed changes due to increased temperature seem to originate from the softening of wet fibers. The observed short time scale phenomena in wet paper have practical significance for fiber webs dried under tension in paper machines. Straining–relaxation–de-straining cycles were used to analyze the effect of heating on the work of straining and apparent plastic and elastic work. Heating affected the amount of mechanical energy absorbed by the sample and the amount of elastic energy recoverable in a straining–relaxation–de-straining cycle. Increased temperature reduced the work of straining and both elastically and plastically absorbed energy. The hysteresis work of the examined wet papers was estimated to correspond to a 1–22 mK temperature change. This suggests that temperature changes in wet paper induced by straining play no role in practice. After mechanical conditioning, tensile stiffness in the re-straining of wet paper depended only marginally on temperature, whereas in initial straining the effect of temperature was clearly stronger. The linear thermal expansion coefficient of wet paper in the machine direction was estimated and the influence of moisture content on the linear thermal expansion coefficient of paper was found to be relatively small.

Evaluation of Some Nonionic Surfactants Derived from Tannic Acid as Additives for Water‐Based Mud

AbstractWater‐based mud is the most‐used mud for oil and gas exploration and is generally considered to be more environmentally friendly than oil‐based or synthetic‐based mud. Therefore in this study we focused on water‐based mud and a series of nonionic surfactants derived from tannic acid was evaluated as additives for water‐based muds. The rheological properties for formulated water‐based muds contain nonionic additives at different temperatures were investigated including: apparent viscosity, plastic viscosity, yield point, gel strength, thixotropy and filtration properties. In addition to the relation between shear stress and shear rate were presented at different temperatures. The results of the studied nonionic surfactant showed improvements in the rheological properties when used as additives for water‐based mud formulation.

A Ti–Zr–Be–Fe–Cu bulk metallic glass with superior glass-forming ability and high specific strength

It has been found that alloying with Cu element could significantly enhance the glass-forming ability (GFA) of Ti–Zr–Be–Fe alloy. As a result, a series of centimeter-scale (Ti41Zr25Be28Fe6)100−xCux (x = 0–20 at.%) bulk metallic glasses (BMGs) have been developed. Especially for those with x = 7–13 at.% Cu content, the critical size is larger than 20 mm. Among these Ti-based BMGs, (Ti41Zr25Be28Fe6)91Cu9 (also noted as Ti37.31Zr22.75Be25.48Fe5.46Cu9) glassy alloy exhibits superior GFA with a critical size larger than 32 mm, which is the largest size of Ti-based BMGs ever reported so far. The enhancement of the GFA is suggested to arise from the Cu addition-induced decrease in both the liquidus temperature and the Gibbs energy difference between the undercooled liquid and the crystalline phases of Ti–Zr–Be–Fe alloy. In addition to its superior GFA, the lightweight (Ti41Zr25Be28Fe6)91Cu9 alloy also exhibits a remarkable high specific strength of 3.7 × 105 N m kg−1 and an apparent plastic strain of 1.2%.