Effect of Bubble Inclusions on the Mechanical Properties of Cast Poly-Methyl Metacrylate

1972 ◽  
Vol 94 (4) ◽  
pp. 847-852 ◽  
Author(s):  
J. D. Stachiw
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Loading Condition ◽  
Stress Raiser ◽  
Compressive Yield Strength ◽  
Compressive Test ◽  
Acrylic Plastic ◽  
Methyl Metacrylate ◽  
As Stress ◽  
Stress Raisers

Bubble inclusions present in cast acrylic plastic generally degrade the mechanical properties of the material. To evaluate the effect of bubbles on the mechanical strength of acrylic plastic, 120 tensile and compressive test specimens were machined from massive acrylic castings with bubble inclusions. The specimens were tested under uniaxial loading condition and effect of bubbles on tensile and compressive strength noted. The stress raiser effect of bubbles caused the tensile specimens to fail at stresses 7 to 30 percent lower than observed in specimens without bubbles. The compressive yield strength was not affected by bubbles. However, here the bubbles served as stress raisers also and caused cracks to initiate at the bubble surfaces when the yield strength of acrylic plastic was reached.

Structural, Physical and Mechanical Properties of Mg-Al Alloys Processed under CO2 Atmosphere

2012 ◽  
Vol 545 ◽  
pp. 247-250 ◽  
Author(s):  
Subramanian Jayalakshmi ◽  
Khoo Chee Guan ◽  
Kuma Joshua ◽  
Manoj Gupta
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Magnesium Alloys ◽  
Physical And Mechanical Properties ◽  
Melting Process ◽  
Al Alloys ◽  
Compressive Yield Strength ◽  
Protective Atmospheres

Magnesium alloys are the lightest structural materials known that are increasingly replacing steel and aluminium. However, due to its flammable nature, protective atmospheres are employed during Mg-alloy production. In this novel work, Mg-Al alloys with ~3 and ~5 wt.% Al were processed in CO2atmosphere, so as to utilize the CO2during the melting process. The cast Mg-Al alloys were extruded and studied for their structural, physical and mechanical properties. Results showed improvements in mechanical properties such as hardness, tensile strength and compressive yield strength. The improvement in properties was attributed to thein situformation of Al4C3arising due to molten metal-carbon interaction. It is noteworthy that the incorporation of CO2during processing did not adversely affect the mechanical properties of the alloys. Further, the process is eco-friendly as it not only utilized CO2, but also eliminates use of harmful cover gases.

scholarly journals Achieving High Yield Strength and Ductility in As-Extruded Mg-0.5Sr Alloy by High Mn–Alloying

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4176
Author(s):  
Shibo Zhou ◽  
Xiongjiangchuan He ◽  
Peng Peng ◽  
Tingting Liu ◽  
Guangmin Sheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Yield Strength ◽  
Tensile Yield Strength ◽  
High Yield ◽  
Compressive Yield Strength ◽  
High Yield Strength ◽  
Pinning Effect ◽  
Small Grains ◽  
Strength And Ductility

The effect of Mn on the microstructure and mechanical properties of as-extruded Mg-0.5Sr alloy were discussed in this work. The results showed that high Mn alloying (2 wt.%) could significantly improve the mechanical properties of the alloys, namely, the tensile and compressive yield strength. The grain size of as-extruded Mg-0.5Sr alloys significantly was refined from 2.78 μm to 1.15 μm due to the pinning effect by fine α-Mn precipitates during the extrusion. Moreover, it also showed that the tensile yield strength and the compressive yield strength of Mg-0.5Sr-2Mn alloy were 32 and 40 percent age higher than those of Mg-0.5Sr alloy, respectively. Moreover, the strain hardening behaviors of the Mg-0.5Sr-2Mn alloy were discussed, which proved that a large number of small grains and texture have an important role in improving mechanical properties.

scholarly journals Utilization of Recycled Thermoplastic Nylon Combined with Virgin Nylon and the Effect on its Mechanical Properties as a Denture Base Material

2019 ◽  
pp. 51-55
Author(s):  
Haslinda Z Tamin ◽  
Siti Wahyuni ◽  
Ismet Danial Nasution
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Modulus Of Elasticity ◽  
Statistical Significance ◽  
Testing Machine ◽  
Base Material ◽  
Bending Test ◽  
Laboratory Research ◽  
Compressive Yield Strength ◽  
Mechanical Degradation

The injection molding process of thermoplastic nylon produces nylon residues in the form of sprue. Nylon residues are non-biodegradable which causes serious ecological problems, hence recycling becomes a necessity. However, recycled nylon is subjected to thermal, oxidative, and mechanical degradation during process which may decrease the mechanical properties of recycled nylon. In order to overcome the decreased mechanical properties of recycled nylon, modification by combining recycled nylon with virgin nylon is considered. Aim: This study aimed to determine the effect of adding virgin nylon into recycled nylon on the modulus of elasticity and compressive yield strength. Settings and Design: Experimental laboratory research. Methods and Materials: A total of 45 samples were used. Samples were divided into 3 groups which include 100% virgin nylon as control (A), 100% recycled nylon (B) and combination of 60% virgin nylon with 40% recycled nylon (C). The samples were tested using Universal Testing Machine (Tensilon RTF, Japan) with three point bending test and compression test with the speed of 5mm/min with ultimate load. Statistical analysis used: The obtained results were analyzed using Univarian test, One-way ANOVA test and Turkey’s Honestly Significant Different test. Result: There was statistical significance in adding virgin nylon into recycled nylon on its mechanical properties, namely modulus of elasticity and compressive yield strength (p<0.05). Conclusion: The combination of 60% virgin nylon with 40% recycled nylon has better elastic modulus and compressive yield strength values compared to 100% recycled nylon.

Microstructure and Mechanical Properties Investigation of New Al10Cr12Mn28Fe(50-x)Ni(x) High Entropy Alloys

2020 ◽  
Vol 998 ◽  
pp. 9-14
Author(s):  
Ahmed W. Abdel-Ghany ◽  
Sally Elkatatny ◽  
Mohamed Abdel Hady Gepreel
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Compressive Yield Strength ◽  
High Entropy Alloys ◽  
High Ductility ◽  
Cast Material ◽  
High Entropy ◽  
Arc Melting ◽  
Microstructure And Mechanical Properties ◽  
Cast Alloys

In the present study, two newly developed non-equiatomic high entropy Al10Cr12Mn28Fe(50-x)Ni(x) alloys (x= 20 & 15 at%, namely: Ni20 & Ni15, respectively) are investigated. The studied HEAs were designed based on thermodynamic principles to maintain high ductility and improve strength. Ingots were prepared using arc-melting then microstructure examinations and mechanical properties for the as-cast alloys were done. The mechanical properties were enhanced for the as-cast material, compared with previously introduced HEAs of the same system, namely Al5Cr12Mn28Fe35Ni20, (Al5) and Al10Cr12Mn23Fe35Ni20, (Al10). Al10Cr12Mn28Fe30Ni20 (Ni20) HEA generally shows the highest compressive yield strength which was improved by ∼7% when compared with previously introduced Al10.

Effect of sintering parameters on the microstructure and compressive mechanical properties of porous Fe scaffold fabricated using 3D printing and pressure less microwave sintering

2020 ◽  
Vol 234 (21) ◽  
pp. 4305-4320
Author(s):  
Dipesh Kumar Mishra ◽  
Pulak Mohan Pandey
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Heating Rate ◽  
Sintering Temperature ◽  
Electron Backscatter Diffraction ◽  
Microwave Sintering ◽  
Compressive Yield Strength ◽  
Soaking Time ◽  
Electron Backscatter ◽  
Backscatter Diffraction

The demand for the porous scaffold has been increasing globally in the biomedical field due to numerous advantages over dense structures like high damping capacity, high specific strength, and improved cell integration growth. In the present study, porous iron scaffolds were fabricated using micro-extrusion-based three-dimensional printing and pressureless microwave sintering. For the preparation of samples, metal-based polymeric ink was developed. Thereafter, cylindrical samples were printed and then sintered in a microwave sintering furnace. The experimental investigations were performed to estimate the effect of sintering parameters such as sintering temperature, heating rate and soaking time on the compressive and microstructural property of the fabricated samples. Microstructural characterization was done using the electron backscatter diffraction technique. The experimental observations deduced that the compressive yield strength and apparent density of the sintered sample increased with the increase in sintering temperature and decreased with a further rise in temperature. Moreover, the electron backscatter diffraction analysis unveiled that the high heating rate resulted in the reduction of compressive yield strength due to rapid grain growth. Additionally, the significant effect of soaking time on the compressive mechanical properties was also noticed due to the increase in the grain size diameter. From the X-ray diffraction plot, it was found that there was no contamination present in the fabricated scaffold. In order to evaluate the process capability, a case study was performed wherein the topologically ordered porous structure of iron was fabricated at optimum sintering parameters.

Structure Change and Improvement of the Mechanical Properties of Lotus-Type Porous Copper by ECAE Process

2009 ◽  
Vol 620-622 ◽  
pp. 757-760 ◽  
Author(s):  
Juan Lobos ◽  
Shinsuke Suzuki ◽  
Hiroshi Utsunomiya ◽  
Hideo Nakajima
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Deformation Behavior ◽  
Cell Walls ◽  
Equal Channel Angular Extrusion ◽  
Structure Change ◽  
Compressive Yield Strength ◽  
Channel Angle ◽  
Porous Copper ◽  
Cylindrical Pores

Deformation behavior of lotus-type porous copper with long cylindrical pores aligned in one direction through equal-channel angular extrusion (ECAE) process was investigated using a die with channel angle of 150º. Although the density slightly increased after every pass, the porous structure remains in the process. The Vickers hardness and the compressive yield strength of lotus copper increased through the ECAE process. The compressive yield strength after 3 passes increased up to 10 times larger than that before processing. The deformation of lotus copper takes place by buckling and the shearing of the cell walls. The increase in hardness is considered to be caused by work hardening.

Material Design of Offshore Linepipe Steels for Ultra Deep Water Application

2019 ◽  
Author(s):  
Kyono Yasuda ◽  
Junji Shimamura ◽  
Satoshi Igi ◽  
Ryuji Muraoka
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Deep Water ◽  
Bauschinger Effect ◽  
Reverse Flow ◽  
Material Design ◽  
Compressive Yield Strength ◽  
Water Application ◽  
Offshore Pipeline ◽  
Lower Temperature

Abstract Offshore pipeline projects have been expanded to deeper water region and the linepipes are required to have higher resistance against collapse by external pressure. The collapse resistance is mainly dominated by pipe geometry and compressive yield strength. For deep water application, diameter to thickness ratio (D/t) and pipe roundness are key factors. On the other hand, the mechanical properties in each circumferential position is dramatically changed by cyclic deformation through a pipe forming process. Therefore, in order to improve compressive yield strength of pipes, it is important to consider the Bauschinger effect caused by pipe expansion. The mechanism of this effect is understood that internal stress is generated by accumulation of dislocation and it reduces reverse flow stress. In this study, the microscopic deformation behavior was analyzed from FEM calculation, it was found that multi-phases microstructure enhanced the microscopic heterogeneous deformation adjacent to the boundary between soft and hard phases. Therefore, homogenized microstructure inhibits the Bauschinger effect. In addition, the materials of offshore pipeline should have other properties such as low temperature toughness and sour resistance. It is well known that fine grained microstructure improves the lower temperature toughness. For achieving high compressive yield strength and good lower temperature toughness, the effect of chemistry and rolling condition were investigated to obtain fine and homogeneous microstructure. Based on laboratory results, mill trial tests were carried out for Grade X65 linepipes with heavy gauge by TMCP. Full scale collapse test was also conducted after pipe coating heating. In this paper, material design concept and its mechanical properties of developed pipes were introduced.

The effect of plastic deformation on mechanical properties of aluminium matrix composites reinforced with 2D crystals

2020 ◽  
Vol 111 (8) ◽  
pp. 632-638
Author(s):  
Jaroslaw Wozniak ◽  
Mateusz Petrus ◽  
Marek Kostecki ◽  
Tomasz Cygan ◽  
Andrzej Olszyna
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Yield Strength ◽  
Physical And Mechanical Properties ◽  
Compressive Yield Strength ◽  
Multilayer Graphene ◽  
Matrix Composites ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
2D Crystals

Abstract In this study, AA6061 matrix composites reinforced with multilayer graphene and MoS2 were analyzed. The composites were prepared by powder metallurgy using the spark plasma sintering and spark plasma texturing methods. Microstructure, physical and mechanical properties were investigated and compared with unreinforced AA6061 sinter and AA6061 sheet plate. The results showed that the application of spark plasma texturing positively influences the relative density and compressive yield strength of AA6061 matrix composites. Moreover, in composites with MoS2, significant differences in compressive yield strength between the centre and the edge of the sintered compacts were noticed. These differences are related to the formation of the MoAl12 phase as a result of the temperature gradient generated in the graphite die during sintering by the spark plasma texturing.

scholarly journals Asymmetry in the Mechanical Properties of Block Ni-Cr-Al Superalloy Foam Fabricated by the Combination of Powder Alloying and Hot Rolling Processes

2020 ◽  
Vol 58 (2) ◽  
pp. 103-111
Author(s):  
Kyu-Sik Kim ◽  
Min-Chul Shim ◽  
Man-Ho Park ◽  
Jung-Yeul Yun ◽  
Kee-Ahn Lee
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Tensile Properties ◽  
Hot Rolling ◽  
Structural Characteristics ◽  
Average Pore Size ◽  
Rolling Direction ◽  
Structural Features ◽  
Compressive Yield Strength ◽  
Average Pore

A block Ni-Cr-Al superalloy foam with dimensions of 300 mm (width direction, WD) × 500 mm (rolling direction, RD) × 60 mm (normal direction, ND) was fabricated using powder alloying, multi-sheet stacking, and hot rolling processes. The structural characteristics, microstructure, and mechanical asymmetry of the block Ni-based foam were investigated. Analysis of the structural features showed that the interfaces between the sheets had complex strut interactions, such as contacted (deformed) and intersected struts. The average pore size along the directions was measured to be 2569.6 μm (WD), 2988.1 μm (RD), and 2493.2 μm (ND). The average thickness of the strut was 340.8 μm, and the wall thickness of the strut was 27.7 μm. The elemental distributions in the struts were uniformly controlled, and the block foam consisted of γ (matrix) and γ ' (Ni<sub>3</sub>Al) phases. Tensile properties in the ND direction showed a yield strength of 0.175 MPa, tensile strength of 0.233 MPa, and elongation of 2.54%, while the tensile properties in the RD direction were 1.27 MPa (YS), 3.01 MPa (UTS), 8.92% (El.) respectively. The foam was observed to have a compressive yield strength of 0.795 MPa in the ND direction, and that of 2.18 MPa in the RD direction were obtained. The asymmetry and anisotropy of these mechanical properties could be explained by the difference in pore sizes along the direction, and the structural characteristics of the sheet interface generated by sheet stacking and rolling.

Investigation of the Mechanical Properties of Lotus-Type Porous Carbon Steel Made by Continuous Zone Melting Technique

2010 ◽  
Vol 638-642 ◽  
pp. 1866-1871 ◽  
Author(s):  
T. Kujime ◽  
Hideo Nakajima
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Steel ◽  
Yield Strength ◽  
Porous Carbon ◽  
Zone Melting ◽  
Compressive Yield Strength ◽  
Compression Tests ◽  
Melting Technique ◽  
Cylindrical Pores

The lotus-type porous carbon steel with cylindrical pores has been fabricated by continuous zone melting technique in pressurized mixture of hydrogen and helium gases. In order to investigate the mechanical properties, the tensile and compression tests were carried out. The ultimate tensile strength of the specimen with cylindrical pores parallel to the solidification direction is lower than the estimated value assuming that the strength is decreased in proportion to decreasing cross section area of the specimen, while the yield strength is higher than that estimated. The compressive yield strength is also higher than that estimated. The increase in yield strength is attributed to the precipitation strengthening. The tensile strength is increased by quenching and tempering, while the elongation decreases. Such mechanical properties are discussed in terms of microstructureal analysis. Furthermore, simulations of the mechanical properties by FEM analysis were carried out.

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