Ultimate Tensile Stress Values Research Articles

Effect of concentration on PVA solutions and its usage in recycling carbon fiber/polyamide 12 prepregs

Abstract Polyvinyl alcohol (PVA) is a biodegradable synthetic polymer with high chemical resistance and excellent mechanical and oxygen barrier properties. Besides these superior properties, it is water-soluble, which provides its wide usage. However, its solubility depends on some factors. Although the temperature is one of these factors and increasing temperature could promote solubility, there is a solubility limit according to hydrolysis degree. In this study, PVA solutions at various concentrations were obtained by mixing fully hydrolyzed PVA1500 and water. Solutions were characterized by density, surface contact angle and dynamic viscosity measurements. Then, solvent casting was used to obtain films, and physical and mechanical properties were determined. Tensile test results showed optimum values at 10–12.5 wt.% PVA concentration. Also, vacuum drying changed the mechanical behavior of films significantly at all concentrations. While ultimate tensile stress values almost doubled and modulus values increased approximately three times, elongations critically decreased. Solutions were also subjected to waste carbon fiber (CF)/polyamide 12 (PA12) prepregs for recycling purposes. Lay-up and compression molding processes were applied to produce CF/PA12 composites. It was seen that mechanical results were significantly increased with increasing PVA concentration.

Effect of titanium on the structural, mechanical and surface properties of CoCrFeMnNiTix high entropy alloy fabricated by selective laser melting

In this study, the effect of titanium (Ti) on the microstructure, mechanical properties, wear resistance and corrosion behavior of CoCrFeMnNi high-entropy alloy (HEA) was examined. The selective laser melting (SLM) method was used to produce HEAs without Ti addition (HEA-1) and with Ti additions of 3 and 5 wt% (HEA-2 and HEA-3, respectively). While the HEA-1 sample exhibited a single-phase face-centered cubic (FCC) structure, the HEA-2 and HEA-3 samples exhibited intermetallic phase structures (Sigma and Laves) along with FCC. The addition of Ti and the presence of intermetallic phases in the HEA-2 sample revealed an improvement in mechanical properties without reducing the ductility value of the structure. However, in parallel with the increasing Ti ratio, the formation of more brittle intermetallic phases in the microstructure of the HEA-3 alloy caused a significant increase in strength but a decrease in ductility. Microstructural examinations revealed that all alloys had a cellular/dendritic structure and the relative densities of the samples were above 99%. While the ultimate tensile stress (UTS) of the HEA-1 sample was 548 MPa and the UTS of the HEA-3 alloy was 832.1 MPa, elongation values were obtained as 48% and 2%, respectively. HEA-2 sample exhibited more ideal results with an elongation value of approximately 22% and UTS values of 760.8 MPa. It was observed that the addition of Ti significantly increased the wear resistance in sliding conditions due to the increase in the hardness of the alloy. The highest hardness and lowest wear rate were obtained with HEA-3 coded samples. The HEA-1 sample exhibited the best corrosion rate, with higher corrosion potential (Ecorr) and lower corrosion current density (Icorr) values. The highest corrosion rate was observed in the HEA-3 sample.

The effect of tooling design and properties of materials on fracture and deformation through equal channel angular pressing technique

The submicrometer range of grain sizes was reached for AA5083 by using equal channel angular pressing at room temperature. While the submicrometer grains of AA5083 were stable up to annealing temperatures of 300 °C, the stability of these grains was only moderately maintained up to annealing temperatures of about 200 °C. Tensile tests conducted after one pass of equal channel angular pressing—that is, strain introduction of roughly one—showed a significant increase in the 0.2% proof stress and ultimate tensile stress values for each alloy. Concurrent with this improvement, the elongations to failure decreased. The analysis shows that the square root of the magnesium content in each alloy corresponds with the magnitudes of these stresses. In samples that were cold rolled, comparable values of proof stresses and ultimate tensile stress were obtained at equivalent strains. However, because of the induction of a very small grain size, elongations to failure were higher after applying equal channel angular pressing to similar strains greater than one. The effects of material constitutive behaviour, tool design, and friction conditions on metal flow, stress fields, and the tendency for tensile fracture during the equal channel angular pressing process were studied using a finite element modelling technique. A degree of non-uniform flow was noted that extended past the head and tail of the extrusion when materials were subjected to equal channel angular pressing with varying constitutive behaviours or when utilising tooling with a radiused front leg. It is anticipated that tool design and material qualities will have a considerable effect on tensile stresses and, in turn, the development of tensile damage during equal channel angular pressing.

Microstructure and mechanical properties of Al/graphite- zirconium oxide hybrid composite fabricated by friction stir processing

Aluminum matrix surface composites (AMSCs) reinforced by various content of zirconium dioxide (ZrO2) nanoparticles and graphite (Gr) microparticles were fabricated by four passes of friction stir processing (FSP). Processing of composites reinforced by Gr particles did not lead to the sound and well-mixed composites due to a decline in the maximum experienced temperature during the process resulting from the low friction coefficient of graphite particles. Combination of graphite and zirconia particles resulted in a more homogenous dispersion of particles in the stir zone (SZ) due to a higher frictional heat generation and a lower tendency for agglomeration of nanoparticles as compared to relevant mono-composites. The occurrence of dynamic recovery (DRV) and dynamic recrystallization (DRX) along with particle stimulated nucleation (PSN) and pinning effect of the particles led to fine and equiaxed grains in the SZ as compared to coarse and elongated grains of the base metal. X-ray diffraction (XRD) analysis demonstrated formation of the Al3Zr intermetallic compounds in Al/ZrO2 nanocomposites because of in-situ reactions. Tensile tests and microhardness measurements showed that the ultimate tensile stress (UTS), yield stress (YS), and microhardness of composites gradually improved by an increase in the weight percent of the secondary phases. The UTS of Al/9 wt% ZrO2, Al/2 wt% Gr, and Al/3 wt% (Gr + ZrO2) with a hybrid ratio of (Gr/ZrO2 = 2) increased ∼42%, ∼53%, and ∼32% as compared to the base metal, respectively. Elongation of composites, especially in graphite-reinforced composites, decreased after FSP. The hybrid composite with a hybrid powder ratio of Gr/ZrO2 = 1 showed the lowest fluctuation of microhardness values because of a uniform particle distribution in the SZ. Hybrid composites with higher Gr content (Gr/ZrO2 = 2) showed greater UTS and microhardness values and lower elongation as compared to other hybrid composites.

Mechanical properties optimization for PLA, ABS and Nylon + CF manufactured by 3D FDM printing

The mechanical characteristics and properties of 3D printed parts are highly influenced by the printing parameters, the printer characteristics, the raw material and the capabilities of the G-code generating software. This work is distinguished by presenting a systematic study to optimize the mechanical properties of PLA, ABS and Nylon + carbon fiber (N + CF) parts manufactured by 3D fused deposition modeling (FDM) printing. To perform the optimization and statistical analysis of the effect of 3D printing parameters (geometric pattern, infill percentage, printing direction and the layer height) on ultimate tensile stress (UTS) and modulus of elasticity (E), two n k designs of experiments (DOE) were systematically applied. In this way, the printing parameters that maximize the UTS and those that are not significant for the three materials were defined which is the main contribution of this work. Additionally, a correlation analysis between density and UTS is presented (R 2 =94.4 %). In the first DOE it was found that the material and the percentage of infill (33 %, 66 % and 100 %) are decisive factors in the impression; the geometric pattern (tridimensional, hexagonal and linear) is no longer relevant and is not considered in the following analysis. In a second DOE it was found that by decreasing the layer height from 0.18 mm to 0.14 mm and modifying the printing direction from 0°/90° to + 45°/− 45° there is an increase in the ultimate tensile stress (UTS) for all three materials. The specimen with the highest UTS reached 85 MPa, which was printed with N + CF linearly with 100 % infill, with 0.14 mm printing layer height and + 45°/− 45° in the printing direction. Through systematic analysis by DOE, it was possible to achieve higher UTS values than their own filaments in the case of N + CF and PLA by 49 % and 18 %, respectively, while for ABS its value is very close to the filament. In conclusion, an algorithm is presented to systematically analyze by DOE to evaluate the hypothesis of achieving a higher UTS than the filament for ABS, PLA and N + CF specimens manufactured by 3D printing.

Influence of sutures configuration on the strength of tendon-patch joints for rotator cuff tears treatment

PurposeMassive rotator cuff tears are common in the aging population. The incidence of failed rotator cuff repairs is still quite high, especially in the treatment of full-thickness tears or revision repairs. In this context, natural and synthetic meshes can be used as augmentation scaffolds or as devices to close the gap between a retracted tendon and the bone.The purpose of this work is to evaluate the ultimate tensile strength of different tendon-patch joints in order to consider their use in the treatment of massive cuff tears. Materials and methodsPorcine tendons and a synthetic low-density polypropylene mesh have been used. A preliminary study on the tensile strength of tendons and patches has been performed. Different patch-tendon joints have been studied by modifying the number and the layout of the sutures. For every joint, the tensile test, performed through an electromechanical machine, has been repeated at least twice to obtain reliable data. ResultsExperimental tensile tests on tendons and patches have given good results with very low dispersion data. Mean values of the calculated ultimate tensile stresses are, respectively, about 34 MPa and 16 MPa for tendons and patches. As regards the sutures arrangement, the staggered layout gave, for all joints, a higher tensile strength than the regular (aligned) one. Different ultimate tensile stress values, depending on the sutures number and layout, have been calculated for the joints. ConclusionSynthetic patches could be an interesting option to repair massive cuff tears and to improve, in a significant way, pain, range of motion and strength at time 0, so reducing the rehabilitation time. Obtained results demonstrated that joints with a suitable number and layout of sutures could ensure very good mechanical performances. The failure load of the tendon-patch joint, in fact, is higher than the working load on a healthy tendon.

Microstructure and properties of functionally graded materials Ti6Al4V/TiC fabricated by direct laser deposition

PurposeThis paper aims to manufacture Ti6Al4V/TiC functionally graded material (FGM) by direct laser deposition (DLD) using Ti6Al4V and TiC powder. The objective is to investigate the effect of process parameters and TiC composition on microstructure, Vickers hardness and mechanical properties.Design/methodology/approachPowder blends with three different volume percentages of Ti6Al4V and TiC were used as feed material for DLD process. Five experiments with different values of laser power and scan speed were conducted to investigate the effect on microstructure and Vickers hardness for different compositions of feed material. Mini-tensile tests were performed to evaluate the mechanical properties of the FGM samples. Digital image correlation (DIC) was applied to estimate Young’s modulus and ultimate tensile stress (UTS) of heterogeneous material.FindingsThis paper indicates that primary carbide, eutectic carbide and un-melted carbide phases are formed in the FGM deposit. As the energy density was increased, the primary and secondary dendrite arm spacing was found to increase. As TiC composition was increased, Young’s modulus increased and UTS decreased. The dendritic morphology of primary TiC growth was expected to cause low resistance for crack propagation, causing lower UTS values. Tensile specimens cut in vertical orientation were observed to possess higher values of Young’s modulus in comparison with specimens cut horizontally at low carbon content.Originality/valueCurrent work presents unique and original contributions from the study of miniature FGM tensile specimens using DIC method. It investigates the effect of specimen orientation and TiC content on Young’s modulus and UTS. The relationship between energy density and dendritic arm spacing was evaluated. The relationship between laser power and scan speed with microstructure and Vickers hardness was investigated.

Evaluation of efficiency and mechanical properties of Inconel 718 components built by wire and powder laser material deposition

PurposeThe purpose of this paper is to evaluate and compare powder and wire laser material deposition (LMD) processes.Design/methodology/approachIn the present paper, Inconel 718 tensile test probes were built layer by layer using a longitudinal strategy, and the quality of the deposited material was characterized for both wire and powder LMD processes. The measured data during the deposition tests have been used for comparing the efficiency of both powder and wire LMD processes. Afterwards, to evaluate the mechanical properties of the parts generated by means of both processes, standard tensile tests were carried out. Furthermore, other factors have been evaluated, such as process reliability or presence of residual material, after the deposition process.FindingsResults show a higher efficiency of the wire LMD process, and even similar ultimate tensile stress values were reached for both processes; powder LMD parts resulted in a more brittle nature.Originality/valueIn the present paper, a thorough analysis that compared both processes has been carried out. The results obtained will help in the future when choosing between wire and powder LMD. The main points of the wealth of knowledge generated with these research efforts are highlighted herein.

Acellularization-Induced Changes in Tensile Properties Are Organ Specific - An In-Vitro Mechanical and Structural Analysis of Porcine Soft Tissues.

IntroductionThough xenogeneic acellular scaffolds are frequently used for surgical reconstruction, knowledge of their mechanical properties is lacking. This study compared the mechanical, histological and ultrastructural properties of various native and acellular specimens.Materials and MethodsPorcine esophagi, ureters and skin were tested mechanically in a native or acellular condition, focusing on the elastic modulus, ultimate tensile stress and maximum strain. The testing protocol for soft tissues was standardized, including the adaption of the tissue’s water content and partial plastination to minimize material slippage as well as templates for normed sample dimensions and precise cross-section measurements. The native and acellular tissues were compared at the microscopic and ultrastructural level with a focus on type I collagens.ResultsIncreased elastic modulus and ultimate tensile stress values were quantified in acellular esophagi and ureters compared to the native condition. In contrast, these values were strongly decreased in the skin after acellularization. Acellularization-related decreases in maximum strain were found in all tissues. Type I collagens were well-preserved in these samples; however, clotting and a loss of cross-linking type I collagens was observed ultrastructurally. Elastins and fibronectins were preserved in the esophagi and ureters. A loss of the epidermal layer and decreased fibronectin content was present in the skin.DiscussionAcellularization induces changes in the tensile properties of soft tissues. Some of these changes appear to be organ specific. Loss of cross-linking type I collagen may indicate increased mechanical strength due to decreasing transverse forces acting upon the scaffolds, whereas fibronectin loss may be related to decreased load-bearing capacity. Potentially, the alterations in tissue mechanics are linked to organ function and to the interplay of cells and the extracellular matrix, which is different in hollow organs when compared to skin.

On the mechanical properties of tooth enamel under spherical indentation

The mechanical properties of tooth enamel generally exhibit large variations, which reflect its structural and material complexity. Some key properties were evaluated under localized contact, simulating actual functioning conditions. Prominent cusps of extracted human molar teeth were polished down ∼0.7mm below the cusp tip and indented by tungsten carbide balls. The internal damage was assessed after unloading from longitudinal or transverse sections. The ultimate tensile stress (UTS) was determined using a novel bilayer specimen. The damage is characterized by penny-like radial cracks driven by hoop stresses and cylindrical cracks driven along protein-rich interrod materials by shear stresses. Shallow cone cracks typical of homogeneous materials which may cause rapid tooth wear under repeat contact are thus avoided. The mean stress vs. indentation strain curve is highly nonlinear, attributable to plastic shearing of protein between and within enamel rods. This curve is also affected by damage, especially radial cracks, the onset of which depends on ball radius. Several material properties were extracted from the tests, including shear strain at the onset of ring cracks γF (=0.14), UTS (=119MPa), toughness KC (=0.94MPam1/2), a crack propagation law and a constitutive response determined by trial and error with the aid of a finite-element analysis. These quantities, which are only slightly sensitive to anatomical location within the enamel region tested, facilitate a quantitative assessment of crown failure. Causes for variations in published UTS and KC values are discussed.

Bake-Hardening Response of High Martensite Dual-Phase Steel with Different Morphologies and Volume Fractions

Bake-hardening behaviour of carbon steel with different martensite morphologies and volume fraction was investigated. The specimens with fibrous and bulky martensite were prestrained in tension by 4%. After this, they were unloaded and bake hardened at 180 °C for 10–160 min. It was found that dual-phase steel samples which were bake hardened at 180 °C for 20 min showed an increase in the yield stress (YS) and ultimate tensile stress (UTS) but a decrease in ductility. Further increase in the bake-hardening time of 80 or 160 min has reduced the YS and UTS, but increased the ductility. Δσ (increase in stress due to bake hardening), YS and UTS values are higher for the microstructure containing fibrous martensite compared to the microstructure-containing bulky martensite. It was also observed that at a given baking temperature Δσ, YS and UTS increased by volume of martensite.

Application of Ball Indentation Technique for Mechanical Properties Estimation of Bi-Metallic Weld

This work studied the ball indentation test at room temperature to characterize the local tensile properties of bi-metallic weld joints. The weld specimens used were fabricated by joining between SA 508 Gr. 3 ferritic steel and Type 304LN stainless steel with Alloy 82 buttering on the ferritic steel side and Alloy 82/182 weld metal. The test results showed that yield stress (YS) of weld metal was slightly higher than that of Type 304 and smaller than that of SA508 Gr.3, and ultimate tensile stress (UTS) of weld metal was similar as those of Type 304 and SA508 Gr.3 base metals. Also, the values of YS and UTS of buttering layer (Alloy 82) were nearly same as those of weld metal. Heat-affected-zones (HAZs) showed higher YS and UTS values compared to their base metals.

Tissue Engineering of Flexor Tendons: The Effect of a Tissue Bioreactor on Adipoderived Stem Cell–Seeded and Fibroblast-Seeded Tendon Constructs

Tissue-engineered flexor tendons could eventually be used for reconstruction of large tendon defects. The goal of this project was to examine the effect of a tissue bioreactor on the biomechanical properties of tendon constructs seeded with adipoderived stem cells (ASCs) and fibroblasts (Fs). Rabbit rear paw flexor tendons were acellularized and seeded with ASCs or Fs. A custom bioreactor applied a cyclic mechanical load of 1.25 N at 1 cycle/minute for 5 days onto the tendon constructs. Three additional groups were used as controls: fresh tendons and tendons reseeded with either ASCs or Fs that were not exposed to the bioreactor treatment and were left in stationary incubation for 5 days. We compared the ultimate tensile stress (UTS) and elastic modulus (EM) of bioreactor-treated tendons with the unloaded control tendons and fresh tendons. Comparison across groups was assessed using one-way analysis of variance with the significance level set at p<.05. Pairwise comparison between the samples was determined by using the Tukey test. The UTS and EM values of bioreactor-treated tendons that were exposed to cyclic load were significantly higher than those of unloaded control tendons. Acellularized tendon constructs that were reseeded with ASCs and exposed to a cyclic load had a UTS of 66.76 MPa and an EM of 906.68 MPa; their unloaded equivalents had a UTS of 47.90 MPa and an EM of 715.57 MPa. Similar trends were found in the fibroblast-seeded tendon constructs that were exposed to the bioreactor treatment. The bioreactor-treated tendons approached the UTS and EM values of fresh tendons. Histologically, we found that cells reoriented themselves parallel to the direction of strain in response to cyclic strain. The application of cyclic strain on seeded tendon constructs that were treated with the bioreactor helped achieve a UTS and an EM comparable with those of fresh tendons. Bioreactor pretreatment and alternative cell lines, such as ASCs and Fs, might therefore contribute to the in vitro production of strong tendon material.

Study on the distortion of steel worm shafts

This paper analyses the root causes for the distortion observed in some C45E grade steel worm shafts during the last steps of machining. Research carried out on two round bars of the steel where distortion was observed and two other ones of a batch machined without distortion were studied. Moreover, two worm shafts in the last steps of the machining process were also analysed. Residual stresses measurements revealed lower and more homogeneous distribution in the bars which do not exhibit the problem. Yield stress and ultimate tensile stress values recorded in the steel of these bars were also lower than those measured in the bars which presented the problem. Metallographic study of the first ones revealed a broken morphology of cementite in the pearlite pointing towards a material stress relieved after the rolling process, eliminating, at least partially, those stresses generated during the deformation of the bar. On the other hand, the pearlite in the steel which suffers distortion looked to be formed during the cooling process after rolling and no given posterior stress relief heat treatment. A stress relief heat treatment of the bars and/or a kinder machining are recommended.

Evaluation of Local Tensile Properties of Bi-Metallic Weld Joints by Small Tensile and Ball Indentation Tests

This study performed tensile test using small-size flat specimen and ball indentation test at room temperature to characterize the local tensile properties of bi-metallic weld joints. The weld specimens used were fabricated by joining between SA508 Gr.3 ferritic steel and Type 316 stainless steel with Alloy 82 buttering on the ferritic steel side and Alloy 82/182 weld metal. The test results showed that yield stress (YS) of weld metal was slightly higher than that of Type 316 and smaller than that of SA508 Gr.3, and ultimate tensile stress (UTS) of weld metal was similar as those of Type 316 and SA508 Gr.3 base metals. Also, the values of YS and UTS of buttering layer (Alloy 82) were nearly same as those of weld metal. Heat-affected-zones (HAZs) showed higher YS and UTS values compared to their base metals. Especially, the strengths of SA508 Gr.3 were significantly higher than those of surrounding materials. Also, it was known that the ball indentation test reasonably measured the local YS and UTS of bi-metallic weld joints.

Long-term creep life prediction for a high chromium steel

Procedures for rationalization and extrapolation of multi-batch creep and creep fracture data, based on relationships which involve only the activation energy for matrix diffusion (300 kJ mol−1) and the ultimate tensile stress values at the creep temperatures, allow straightforward prediction of the 100,000 h creep rupture strengths of 11Cr–2W–0.4Mo–1Cu–Nb–V steel (Grade 122).

Fatigue behaviour of oil palm fruit bunch fibre/epoxy and carbon fibre/epoxy composites

Unidirectional tensile tests were carried out on oil palm fruit bunch fibre (OPFBF)/epoxy composite and carbon fibre (CF)/epoxy composite to determine their modulus and ultimate tensile stress (UTS). The UTS determined from these tests were then used as the fatigue test parameters. Two different values of fibre volume ratios, V f, namely 35% and 55% were studied for OPFBF/epoxy composite. Fatigue tests using constant stress amplitude were carried out for OPFBF/epoxy and CF/epoxy composites at the stress ratios of 0.1 and 0.5 and frequency of 20 Hz. The results for tensile properties and fatigue behaviour as well as failure mechanism were evaluated. The results show that the UTS values for OPFBF is 24.9 MPa and for OPFBF/epoxy composite with 35% fibre volume ratio is 47.78 MPa.

Mechanical tensile properties of the quadriceps tendon and patellar ligament in young adults.

We analyzed mechanical tensile properties of 16 10-mm wide, full-thickness central parts of quadriceps tendons and patellar ligaments from paired knees of eight male donors (mean age, 24.9 years). Uniaxial tensile testing was performed in a servohydraulic materials testing machine at an extension rate of 1 mm/sec. Sixteen specimens were tested unconditioned and 16 specimens were tested after cyclic preconditioning (200 cycles between 50 N and 800 N at 0.5 Hz). Mean cross-sectional areas measured 64.6 +/- 8.4 mm2 for seven unconditioned and 61.9 +/- 9.0 mm2 for eight preconditioned quadriceps tendons and were significantly larger than those values of seven unconditioned and seven preconditioned patellar ligaments (36.8 +/- 5.7 mm2 and 34.5 +/- 4.4 mm2, respectively). Mean ultimate tensile stress values of unconditioned patellar ligaments were significantly larger than those values of unconditioned quadriceps tendons: 53.4 +/- 7.2 N/mm2 and 33.6 +/- 8.1 N/mm2, respectively. Strain at failure was 14.4% +/- 3.3% for preconditioned patellar ligaments and 11.2% +/- 2.2% for preconditioned quadriceps tendons (P = 0.0428). Preconditioned patellar ligaments exhibited significantly higher elastic modulus than preconditioned quadriceps tendons. Based on mechanical tensile properties analyses, the quadriceps tendon-bone construct may represent a versatile alternative graft in primary and revision anterior and posterior cruciate ligament reconstruction.

Influence of Fatigue Damage on Ultimate Tensile Stress of Sintered Iron

Conventional powder metallurgical techniques have been employed to manufacture two levels of sintered porosities in technically pure iron. The porous iron specimens were cyclically loaded with a number of cycles n lower than their expected life N then quasistatically pulled to failure. The ultimate tensile stress (UTS) values of these damaged specimens have been compared with UTS values of virgin specimens. It has been shown that static resistance (UTS) decreases almost linearly with cumulative damage at repeated loading. The decrease in UTS is greater at higher porosity levels and when a tensile (positive) mean stress is used for the cyclic loading. PM/0749

High strength Al metal-matrix microcomposite wire with 20 vol% Nb and ultimate tensile strengths up to 1030 MPA

In conventional composite structures a property F can often be related to the properties of the individual components through the rule of mixtures (ROM). Metal-matrix structures in which the second metal B is finely dispersed can have properties that deviate strongly from the ROM. Several binary systems have been extensively investigated, notably Cu-Nb and Ag-Cu. These binary mixtures are typically produced by means of casting or powder metallurgy. The powder metallurgy (PM) route allows the production of a billet without melting, and can prevent the formation of solid solutions. Mechanical deformation to high strains of these casts or PM billets by extrusion and wire drawing produces a very fine filament size of the minority phase. These microcomposites have a filament thickness in the range of 10-200 nm or less. At high [eta] (strain) the ultimate tensile stress (UTS) of the mixtures exceeds the UTS calculated with the rule of mixtures UTS[sub ROM]. For proper UTS[sub ROM] calculations UTS values of the pure constituents that have been strained over a comparable range must be used. In a recent study Spitzig measured a UTS of 1400 MPa for cast Nb deformed to [eta] = 11.5. In the present work a 100% Nbmore » wire using Nb powder, deformed to [eta] = 12.8, had a UTS of 1440 MPa. For cu the authors assumed 495 MPa (1) at [eta] = 11.5. The authors found similar strengthening effects in Al-Nb PM wires. The strengthening is measured in wires in which Al is the majority phase, but also in wires with Nb as the majority phase.« less