Shear Punch Test Research Articles

Study on the effect of cooling rate on the solidification parameters, microstructure, and mechanical properties of LM13 alloy using cooling curve thermal analysis technique

In this study, the effect of cooling rate on the microstructure, solidification parameters, and mechanical property of LM13 alloy has been investigated. To obtain different cooling rates, an air-cooled graphite mold, 3 sand molds with different moisture content, a water-cooled graphite mold, and a water-cooled steel mold were used. The cooling rates and the solidification parameters were determined by using computer-aided thermal analysis method. Results show that with increasing cooling rate from 1.1 to 50°C/s, secondary dendrite arm spacing decreases 65%. At higher cooling rates, the nucleation temperature of reactions shifts to higher temperature, except the final reaction, but the eutectic recalescence undercooling is eliminated. It modifies eutectic microstructure and decreases parallel eutectic layers distance from 23.24 to 4μm. In addition, it reduced primary silicon particle appearance (PSPA) from 1.17 to 0.3. The equivalent porosity diameter also reduces from 72.5μm to 27.8μm. Shear punch test (SPT) shows improvement of ultimate shear stress, yield shear stress, and normalized displacement at higher cooling rates. Hardness has also been improved about 30 Vickers as a result of increasing cooling rate.

Strain rate sensitivity of equal-channel angularly pressed Sn–5Sb alloy determined by shear punch test

The strain rate sensitivity (SRS) of a fine-grained Sn–5wt% Sb alloy, processed by equal-channel angular pressing (ECAP), was investigated by shear punch testing (SPT) at room temperature. The microstructural homogeneity increased with increasing the number of ECAP passes, and the grain size decreased from 3.2 to 2.5μm, as the number of passes increased from 1 to 4. Results showed that the deformation response of the material after 4 ECAP passes conforms to regions I, II and III, typical of superplastic behavior. In region II, the SRS index of the shear yield stress was significantly strain dependent, being 0.23 and 0.57, after 1 and 4 passes, respectively. The high SRS index of 0.57 is indicative of a superplastic deformation behavior dominated by grain boundary sliding.

Effect of ^|^eta; Phase on Mechanical Properties of the Iron-based Superalloy Using Shear Punch Testing

In this paper, the shear deformation behavior of A286 Iron-based superalloy was studied with an emphasis on the influence of η phase on shear strength. The η (Ni3Ti) phase precipitates at high temperature heat treatment or during services at the expense of gamma prime phase. According to the microstructural features, no evidences of η phase were found at 650 and 720°C. η phase precipitated at 780 and 840°C and the amount of it increased with an increase the time and temperature. Because of using the alloy as fasteners, investigation of shear properties and the influence of η phase on it are indispensable. The shear strength of the alloy with different volume fractions of η was examined. It was found that, with an increase of η volume fraction, the ultimate shear strength decreases. The shear punch fracture surfaces were also examined by the scanning electron microscopy. The fracture surfaces of sheared samples indicated that low and high volume fraction of η phase result in interior cracks and grain boundary decohesion, respectively. In fact, the fracture of weak grain boundary films (η phase) produces this kind of decohesive cracking.

Effect of dietary solvents on the strength of nanocomposite, compomer, glass ionomer cement: An in-vitro study

Background:Intraoral degradation of resin restorative materials involves both mechanical and chemical factors. Thus, an in vitro study was conducted to compare the strength of nanocomposite to commonly used esthetic restorative materials in simulated in vivo conditions.Aim:The aim of this study was to determine the influence of dietary solvents on the strength of nanocomposite and other esthetic restorative materials.Materials and Methods:Three test groups (nanocomposite, compomer and glass ionomer cement) each containing 60 pre-conditioned samples, divided into four subgroups of 15 samples each and conditioned in different dietary solvents, were subjected to shear punch test in custom designed shear punch apparatus in Instron Universal Testing Machine.Statistical Analysis:Descriptive statistics, one way analysis of variance (ANOVA), paired t-test were implied.Results:One-way ANOVA revealed nanocomposite to bear most shear punch strength post-conditioning, as compared with the other two test materials.Conclusion:Nanocomposite yielded better strength than the other two test materials, indicating its universal application as a restorative material.

Assessment of tensile properties of spot welds using shear punch test

Standard test procedures are difficult to employ for determining tensile properties of spot welds due to their small volume. In order to overcome this limitation, attempts have been directed here to assess tensile properties of spot welds made on interstitial free (IF) steel sheets using shear punch tests. These experiments have been supplemented with microstructural examinations using optical, SEM and TEM, standard tensile tests, microhardness tests, and fractographic studies in order to understand in-depth tensile behavior of spot welds. The obtained results assist to infer that strength values obtained from tensile tests of varyingly pre-strained IF steel sheets are linearly correlated with their corresponding shear strength values obtained from shear punch tests. Based on the above linear correlation, the tensile and yield strength of the weld nuggets have been estimated for the first time using shear punch test. The estimated strength values of the weld nugget region are found to be higher compared to that of the base metal; this has been explained by considering the microstructural constituents formed at the fusion zone during the welding process.

Characterization of newly developed semisolid stir welding method for AZ91 magnesium alloy by using Mg–25%Zn interlayer

Semisolid stir joining of AZ91 alloy was investigated by using mechanical stirring and Mg–25wt%Zn interlayer. A 2mm-thick interlayer was located between two 7.5mm-thick AZ91 pieces. Then, they were heated to 530°C, the semisolid temperature of both base metal and interlayer. A stirrer with a rotational speed of 1600rpm was introduced into the weld seam. Optical microscopic and scanning electron microscope (SEM) investigation, microhardness test, shear punch test (SPT), and three points bending test were carried out to assess the properties of the joint. Results showed three distinctive zones: stir zone (SZ), compacted zone (CZ), and diffusional–mechanical affected zone (DMAZ). SEM and X-ray diffraction (XRD) analysis also indicated a wide range of compounds formed in the different zones. The macroscopic image also showed advancing and retreating sides with different DMAZ widths. Proper metallurgical bonding was achieved due to the satisfactory mixing of base metal and interlayer in the semisolid condition. Shear punch test also showed decent ultimate shear strength of the weld metal.

Correlation of tensile test properties with those predicted by the shear punch test

In the development of experimental alloys having sufficient material to do a standard tensile test procedure is not always possible. Thus in this work, we have evaluated the ability of the shear punch test to predict the strength and ductility of materials in place of the tensile test.This correlation study was carried out experimentally using six different alloys, and validated using finite element modelling. Both the experimental and modelling data confirmed that the yield point and ultimate tensile stress can be accurately elucidated from the shear punch data.However, the punch displacement at failure was found to be a function of both the ductility of the material and its work hardening rate. Although corrections were developed using the FE simulations which satisfactorily predicted tensile ductility from to the simulated shear punch displacement, back extrapolation of the tensile ductility from experimentally measured shear punch tests were not possible.It was concluded that the shear punch test suitable for determining the strength of a material, but not able to be used to infer the equivalent tensile ductility due to both experimental error in determining the point of failure as well as the interdependence of the punch displacement on multiple material properties.

Effect of zirconium on grain growth and mechanical properties of a ball-milled nanocrystalline FeNi alloy

Grain growth of ball-milled pure Fe, Fe92Ni8, and Fe91Ni8Zr1 alloys has been studied using X-ray diffractometry (XRD), focused ion beam (FIB) microscopy and transmission electron microscopy (TEM). Mechanical properties with respect to compositional changes and annealing temperatures have been investigated using microhardness and shear punch tests. We found the rate of grain growth of the Fe91Ni8Zr1 alloy to be much less than that of pure Fe and the Fe92Ni8 alloy at elevated temperatures. The microstructure of the ternary Fe91Ni8Zr1 alloy remains nanoscale up to 700°C where only a few grains grow abnormally whereas annealing of pure iron and the Fe92Ni8 alloy leads to extensive grain growth. The grain growth of the ternary alloy at high annealing temperatures is coupled with precipitation of Fe2Zr. A fine dispersion of precipitated second phase is found to promote the microstructural stability at high annealing temperatures and to increase the hardness and ultimate shear strength of ternary Fe91Ni8Zr1 alloy drastically when the grain size is above nanoscale.

An investigation into the room temperature mechanical properties of nanocrystalline austenitic stainless steels

The present work has been conducted to evaluate the mechanical properties of nanostructured 316L and 301 austenitic stainless steels. The nanocrystalline structures were produced through martensite treatment which includes cold rolling followed by annealing treatment. The effect of equivalent rolling strain and annealing parameters on the room temperature mechanical behavior of the experimental alloys have been studied using the shear punch testing technique. The standard uniaxial tension tests were also carried out to adapt the related correlation factors. The microstructures and the volume fraction of phases were characterized by transmission electron microscopy and feritscopy methods, respectively. The results indicate that the strength of nanocrystalline specimens remarkably increases, but the ductility in comparison to the coarse-grained one slightly decreases. In addition the strength of nanocrystalline specimens has been increased by decreasing the annealing temperature and increasing the equivalent rolling strain. The analysis of the load–displacement data has also disclosed that the universal correlation of linear type (UTS=mτmax) between shear punch test data and the tensile strength is somehow unreliable for the nanocrystalline materials. The results suggest that the actual relation between the maximum shear strength and ultimate tensile strength follows a second order equation of type UTS=aτmax2-bτmax+c.

Severe plastic deformation of rheoforged aluminum alloy A356

In this research, the electromagnetic stirring (EMS) process was used to produce semi-solid slurry with globular structure from cast A356 aluminum alloy. Then the slurry was forged in a die, which named rheoforging process. Utilizing multidirectional forging (MDF), the effect of severe plastic deformation on microstructure and mechanical properties of this alloy in dendritic and globular states was investigated. Shear punch, micro- and macro-hardness tests were used to study the mechanical properties of these samples. For metallographic examinations, the optical microscope equipped with the Clemex® image analyzer software was used. Optimum globular structure of rheoforged specimens was achieved to deform those in three successful passes of MDF. The results show that more severe strain can be imposed on globular structure with respect to dendritic one. Also, MDF process can effectively improve the strength of the samples with no noticeable change in globules morphology of the rheoforged samples.

Shear Property of Pb-Free Solder Joint According to Temperature Condition by SP and FEM

The use of Pb-free solder alloys are just newly developed materials and their properties are not well established and documented yet. So, the research to substitute the critical problem of the Pb solder alloy are increasing widely. To evaluate the shear property of solder joints according to temperature condition was predicted through the Shear-Punch test and FEM. By using the database according to this, the reliability evaluation technology of the solder joints tries to be formulated. In this paper, the solder used the Sn37Pb, Sn-4Ag and the Sn4Ag0.5Cu. When solder melted in the copper interface, the solder joints according to reflow times, each modeling required for the Shear- Punch was made in consideration of the IMC layer thickness. And the micro shear punch test was performed to obtain material properties of solder according to temperature condition. The shear properties of specimen which was modeled was predicted through FEM. It compared with the test value in which it obtains from Shear-Punch. Also, a method which can obtain shear properties of Pb-free solder joints easily and quickly using FEM was proposed.

Evaluating the mechanical properties of a thermomechanically processed unmodified A356 Al alloy employing shear punch testing method

The effects of thermomechanical processing (TMP) parameters on the microstructure evolution and final mechanical properties of an unmodified A356 Al alloy have been investigated. The evaluation of mechanical properties was carried out using shear punch testing (SPT) method. The applied TMP cycles encompassed a set of isothermal hot compression tests in the temperature range of 420–540°C under various strain rates of 0.001, 0.01 and 0.1s−1. The results indicate that increasing both the TMP temperature and strain rate has enhanced the room temperature strength of the experimental alloy. Furthermore, while ductility follows a similar improving trend with increasing the TMP temperature, it is deteriorated by increasing the strain rate. The obtained results are reasoned debating the role of solute atoms and the changes in Si particles shape and size. The present work also made use of quality index (Q) to measure the mechanical performance of the TMPed unmodified A356 Al alloy.

Microstructural homogeneity, texture, tensile and shear behavior of AM60 magnesium alloy produced by extrusion and equal channel angular pressing

Equal channel angular pressing (ECAP) experiments with various pass numbers were conducted for the extruded AM60 magnesium alloy to investigate the influence of the operation on the microstructure and mechanical properties of the alloy. By this means, the grain structure of the material was refined from 19.2μm to 2.3μm after 6 passes at 220 °C. The shear punch testing (SPT) and uniaxial tensile tests were employed to evaluate the mechanical properties of the extruded and ECAPed samples. Both the yield stress (YS) and ultimate strength (US) obtained from the shear punch and tensile tests increased just after two passes but decreased with further pressing, though the grains became finer with increasing the pass number. The 6-pass ECAPed AM60 showed lower yield stress and higher ductility compared with the as-extruded material, indicating that texture softening overcame the strengthening effects of the grain refinement. The good correlation between the shear and tensile data obtained in the present investigation showed that SPT was a useful method for evaluation of the mechanical properties of the ECAPed fine-grained materials. The Vickers microhardness was also recorded on the polished cross sections of each sample and the results were plotted in the form of color-coded maps in order to provide a graphical presentation of the hardness distribution. It was found that the improvement in the homogeneity of hardness with a greater number of passes was due to a reasonably homogeneous microstructure throughout the product.

Characterization of mechanical properties and microstructure of highly irradiated SS 316

Cold worked austenitic stainless steel type AISI 316 is used as the material for fuel cladding and wrapper of the Fast Breeder Test Reactor (FBTR), India. The evaluation of mechanical properties of these core structurals is very essential to assess its integrity and ensure safe and productive operation of FBTR to very high burn-ups. The changes in the mechanical properties of these core structurals are associated with microstructural changes caused by high fluence neutron irradiation and temperatures of 673–823K. Remote tensile testing has been used for evaluating the tensile properties of irradiated clad tubes and shear punch test using small disk specimens for evaluating the properties of irradiated hexagonal wrapper. This paper will highlight the methods employed for evaluating the mechanical properties of the irradiated cladding and wrapper and discuss the trends in properties as a function of dpa (displacement per atom) and irradiation temperature.

Evaluation of Tensile Properties of Pressure Vessel Materials by Shear Punch Test Method

A shear punch test is a very useful small specimen test method for evaluating the mechanical properties of in-service components, in view of the requirements of small size sample material. This paper presents the results of shear punch tests on five grades of steels used in boiler construction, along with the correlation with yield stress and ultimate tensile stress obtained ASTM standard specimens. The design of the shear punch fixture and procedure to carry out the shear punch test is also highlighted.

Correlation Between Shear Punch and Tensile Strength for Low-Carbon Steel and Stainless Steel Sheets

The deformation behavior of AISI 1015 low-carbon steel, and AISI 304 stainless steel sheets was investigated by uniaxial tension and the shear punch test (SPT). Both materials were cold rolled to an 80% thickness reduction and subsequently annealed in the temperature range 25-850 °C to produce a wide range of yield and ultimate strength levels. The correlations between shear punch and tensile yield and ultimate stresses were established empirically. Different linear relationships having different slopes and intercepts were found for the low-carbon and stainless steel sheets, and the possible parameters affecting the correlation were discussed. It was shown that, within limits, yield and tensile strength of thin steel sheets can be predicted from the shear data obtained by the easy-to-perform SPT.

Hot shear deformation constitutive analysis of an extruded Mg–6Li–1Zn alloy

The hot shear deformation behavior of an extruded Mg–6Li–1Zn alloy was investigated by shear punch test (SPT) in the temperature range 473–573K, and in the shear strain rate range 1.2×10−3–6.0×10−2 s−1. Based on the constitutive analysis of the SPT data, it was found that a sine hyperbolic function could properly describe the hot shear deformation behavior of the material. The activation energy of 90–110kJ mol−1 calculated from sine hyperbolic function together with the power-law stress exponents of 3.8–5.4 is indicative of a pipe‐diffusion‐controlled dislocation viscous glide mechanism as an operative deformation mechanism.

Fabrication of porous NiTi alloy via powder metallurgy and its mechanical characterization by shear punch method

In this study, Porous NiTi shape memory alloy has been produced by mechanical alloying of the elemental Ni and Ti powders. The compacting process was done at two temperatures (warm and cold press) and then sintering at 980 and 1050°C was performed on the specimens. Microstructure and mechanical prop-erties of the samples were investigated by optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction. Moreover, shear punch test (SPT) employed to investigate the effect of compaction pressure and sintering temperature on the mechanical properties of the fabricated samples. It was revealed that warm compaction/sintering resulted in 15% yield stress improvement and 20% ultimate tensile strength (UTS) enhancement with respect to conventionally produced specimens. The proposed approach in this paper seems a step forward towards fulfillment of the demand for heavy load-bearing artificial bone.

Electrochemical behavior of cold sprayed hydroxyapatite/titanium composite in Hanks’ solution

A novel approach-cold spraying technique has been successfully used to deposit HAP/Ti composite coating on titanium substrate. The electrochemical corrosion behavior of cold sprayed 20wt% and 50wt% HAP/Ti composite coating has been evaluated in a simulated biomedical environment. X-ray diffraction (XRD) analysis and scanning electron microscopy were applied to identify the phases and the morphologies of the coatings. Potentiodynamic polarization and EIS techniques were used to analyze the corrosion behavior in Hanks’ solution. The microhardness measurements and shear punch tests were also conducted to investigate the mechanical property. It was found that cold sprayed 20wt% HAP/Ti coating showed relatively higher corrosion current than pure Ti and 50wt% HAP/Ti coating in Hanks’ solution, which indicates a low corrosion resistance. However, the post spray heat treatment improved the corrosion and mechanical properties remarkably. The results obtained in the present work demonstrate suitability of cold spraying technique to manufacture HAP/Ti composite coating on titanium substrate as load-bearing implant material for biomedical applications.

Effect of Annealing on the Microstructure, Texture and Mechanical Properties of Severely Deformed Interstitial Free Steel

Ti-stabilised interstitial free (IF) steel initially subjected to 8 passes, route BC equal channel angular pressing (ECAP) was further cold rolled (CR) at room temperature to 95% thickness reduction. Both samples were isothermally annealed at 710 °C following which their microstructures and micro-textures were compared via electron back-scattering diffraction (EBSD). The mechanical properties first obtained by shear punch testing (SPT) were later corroborated by uniaxial tensile tests. In the case of the ECAP material, continuous recrystallisation is followed by abnormal growth at prolonged annealing times with minor increases in high angle boundary (HAGB) fraction. On the other hand, the additionally CR material shows continuous recrystallisation accompanied by a reduction in the HAGB fraction. After 15 s annealing, the ECAP and CR samples exhibit a good strength-ductility balance; which corresponds to ~52% and ~67% softening, respectively.