scholarly journals Estimation of the Effect of Production Parameters on Mechanical Properties of Sintered Steels using ANOVA

2017 ◽  
Vol 62 (2) ◽  
pp. 571-576
Author(s):  
M. Sułowski ◽  
A. Jordan ◽  
A. Czarski ◽  
P. Matusiewicz

Abstract The object of the study was to assess the influence of selected production parameters of sintered Fe-Mn-Cr-Mo-C steels i.e. chemical composition, sintering temperature, sintering atmosphere and heat treatment on the following mechanical properties: impact toughness, hardness of the surface, tensile strength, bend strength after static tensile tests. In the investigations, the general linear model (GLM) of the multivariate analysis of variance ANOVA was used. All assumptions of ANOVA, i.e. randomization of the experiment, the normality of the residuals, equality of variance at different levels have been fulfilled and verified. The predictive strength of the constructed models expressed by the adjusted determination coefficient (R2adj) is at medium or large level – R2adj is in the range from 41.46% to 76.97%. This work is focused mainly on the ANOVA methodology. A wide physical interpretation of the results will be possible after the optimization of the ANOVA models used.

1999 ◽  
Author(s):  
Takeru Ohki ◽  
Shinya Ikegaki ◽  
Ken Kurasiki ◽  
Hiroyuki Hamada ◽  
Masaharu Iwamoto

Abstract In this study, fracture behavior and strength in the flat braided bar with a circular hole were investigated by static and fatigue test. Two type of specimens were prepared. They are a braided flat bar with an integrally-formed braided hole and a braided flat bar with a machined hole. Moreover, we also examined a specimen that had a metal pin inserted at the circular hole. This specimen was subjected to a static tensile test. The results of the tensile tests indicate that the strength of the flat bar with a braided hole was larger than that of the one with the machined hole. Furthermore, from the results of the fatigue tests, the flat bar with the braided hole showed higher fatigue property than that of the one with the machined hole.


2016 ◽  
Vol 1133 ◽  
pp. 85-89
Author(s):  
Mohamad Azmirruddin Ahmad ◽  
Fazira Suriani Mohamed Fadzil ◽  
Mazlan Mohamad ◽  
Mohamad Hasnan Abdul Hamid ◽  
Mohd Asri Selamat

Their excellent properties, such as corrosion resistance, fatigue strength and bio-compatibility, made Cobalt-chromium-molybdenum (CoCrMo) were used in total hip and knee replacements and dental devices. The green CoCrMo compacts specimens in rectangle shape were fabricated by powder pressing technique. The effects of sintering temperature and atmosphere on the mechanical properties and microstructure of the CoCrMo compacts which is sintered at 1300°C-1400°C under two different inert gases sintering atmosphere (Ar2/N2H2) were investigated. The experimental results show that the grain boundaries sizes of CoCrMo compact sintered specimen were increased with increasing sintering temperature. The CoCrMo compacts specimens sintered at 1350°C under inert gases N2H2 atmosphere possess highest density (8.096 g/cm3) and hardness (327.1Hv). However, when the compacts specimens are sintered at 1400°C, the density (7.596 g/cm3) and hardness (320 Hv) properties of sintered compact were decreased.


2000 ◽  
Vol 122 (4) ◽  
pp. 420-424 ◽  
Author(s):  
Takeru Ohki ◽  
Shinya Ikegaki ◽  
Ken Kurasiki ◽  
Hiroyuki Hamada ◽  
Masaharu Iwamoto

In this study, fracture behavior and strength in the flat braided bar with a circular hole were investigated by static and fatigue test. Two types of specimen were prepared. They are a braided flat bar with an integrally formed braided hole and a braided flat bar with a machined hole. Moreover, we also examined a specimen that had a metal pin inserted at the circular hole. This specimen was subjected to a static tensile test. The results of the tensile tests indicate that the strength of the flat bar with a braided hole was larger than that of the one with the machined hole. Furthermore, from the results of the fatigue tests, the flat bar with the braided hole showed higher fatigue property than that of the one with the machined hole. [S0094-4289(00)02604-9]


2014 ◽  
Vol 59 (4) ◽  
pp. 1637-1640 ◽  
Author(s):  
J. Dworecka ◽  
E. Jezierska ◽  
K. Rozniatowski ◽  
W. Swiatnicki

Abstract The aim of the work was to produce a nanobainitic structure in the commercial bearing steel - 100CrMnSi6-4 and to characterize its structure and mechanical properties. In order to produce this structure the austempering heat treatment was performed, with parameters that have been selected on the basis of dilatometric measurements of phase transformation kinetics in steel. The heat treatment process was performed in laboratory as well as in industrial furnaces. The obtained structure was characterized using transmission electron microscopy. In order to investigate the effect of the microstructure parameters on the material’s mechanical properties, the hardness, impact strength and static tensile tests have been conducted.


2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040036
Author(s):  
Yongjun Su ◽  
Yunfeng Lin ◽  
Na Zhang ◽  
Deliang Zhang

This work deals with the consolidation of a TiAl alloy powder by spark plasma sintering (SPS). Pre-alloyed powder with a composition of Ti–48Al–2Cr–2Nb (at.%) was consolidated in a SPS furnace at temperatures between 1200[Formula: see text]C and 1325[Formula: see text]C and with a pressure of 50 MPa. The microstructures obtained after SPS depend on the sintering temperature. Tensile tests at room temperature were performed. The alloy SPSed at temperatures not less than 1250[Formula: see text]C exhibits good properties at room temperature.


2015 ◽  
Vol 60 (4) ◽  
pp. 2543-2548 ◽  
Author(s):  
P. Kulecki ◽  
E. Lichańska ◽  
M. Sułowski

The object of the study was to evaluate the effect of production parameters on the structure and mechanical properties of Cr and Cr-Mo PM steels. The measurements were performed on sintered steels made from commercial Höganäs pre-alloyed powders: Astaloy CrA, Astaloy CrL and Astaloy CrM mixed with carbon, added in the form of graphite powder grade C-UF.Following mixing in a Turbula mixer for 30 minutes, green compacts were single pressed at 660 MPa according to PNEN ISO 2740 standard. Sintering was carried out in a laboratory horizontal furnace at 1120°C and 1250°C for 60 minutes, in 5%H2-95%N2atmosphere. After sintering, the samples were tempered at 200°C for 60 minutes in air. The steels are characterized by ferritic - pearlitic, bainitic - ferritic and bainitic structures.Following mechanical testing, it can be assumed that steel based on Astaloy CrA pre-alloyed powder could be an alternative material for steels based on Astaloy CrL powder. These steels sintered at 1250°C with 0.6% C had tensile strengths about 650 MPa, offset yield strengths about 300 MPa, elongations about 8.50 %, TRSs about 1100 MPa, hardnesses 220 HV.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5224
Author(s):  
Anna Wójcicka ◽  
Krzysztof Mroczka ◽  
Jerzy Morgiel

The elaboration of a modified friction-extrusion method aimed at obtaining 2017A aluminum rods of gradient microstructure is described. This was achieved by cutting spiral grooves on the face of the stamp used for alloy extrusion. The experiments were carried out at a constant material feed (~10 mm/min) and a range of tool rotation speeds (80 to 315 rpm). The microstructure observations were carried out using light microscopy (LM) and both scanning and transmission electron microscopy (SEM and TEM). The mechanical properties were assessed through hardness measurements and static tensile tests. The performed investigations show that material simultaneous radial and longitudinal flow, enforced by friction of the rotating tool head and extrusion, results in the formation of two zones of very different microstructures. At the perpendicular section, the outer zone stands out from the core due to circumferential elongation of strings of particles, while in the inner zone the particles are arranged in a more uniform way. Simultaneously, the grain size of the outer zone is refined by two to four times as compared with the inner one. The transfer from the outer zone to the core area is of gradient type. The hardness of the outer zone was found to be ~10% to ~20% higher than that of the core.


2013 ◽  
Vol 592-593 ◽  
pp. 425-428
Author(s):  
Ming Hwa R. Jen ◽  
Che Kai Chang ◽  
Bo Cyuan Lin

The aims of this study are to fabricate Ti/APC-2 hybrid composite laminates with and without (W/WO) nanoparticles and investigate the mechanical properties of laminates with single-edged cracks due to both tensile and cyclic tests. The mechanical properties such as ultimate tensile strength and longitudinal stiffness of original composite laminates W/WO nanoparticles were first obtained from the static tensile tests. However, the load-displacement diagrams were plotted for the crack laminates. The constant stress amplitude tension-tension cyclic tests were conducted to receive the S-N curves and fatigue data. The ultimate strengths for both Ti/APC-2 composite laminates W/WO nanoparticles were very close at varied crack length. Ti/APC-2 cross-ply nanocomposite laminates had better fatigue resistance than that of laminates without nanoparticles. The longer the crack length is, the more their properties are reduced. Also, the values of fracture toughness of both hybrid cracked laminates W/WO nanoparticles were obtained by rule of mixtures and found acceptable. Finally, in predicting crack growth rate and residual life, instead of commonly used Paris Law for metals, the modified method was adopted for hybrid cracked laminates. The prediction is not satisfactorily acceptable, even if most results are in good agreement with empirical data.


Author(s):  
M. Mrówka ◽  
M. Szymiczek ◽  
J. Lenża

Purpose: Thermoplastic polyurethanes (TPU) found application in mining. Due to the excellent processing properties, thermoplastic polyurethanes can be also use to make elements that would facilitate miner's work. These elements, however, differ in dimensions depending on the person who is going to use them, that is why they should be personalized. In case of all the above studies, the elements or stuffs were made by means of the injection method. This method limits the possibility of producing mining’s stuff only to models that have a mould. The 3D printing technology developing rapidly throughout the recent years allows for high-precision, personalized elements’ printing, made of thermoplastic materials. Design/methodology/approach: The samples from thermoplastic polyurethanes were made using 3D printing and then subjected to the aging process at intervals of 2, 7 and 30 days. The samples were then subjected to a static tensile tests, hardness tests and FT-IR spectroscopy. Findings: The obtained results of mechanical tests and IR analyses show that the aging process in mine water does not affect the mechanical properties of the samples regardless of the aging time. IR spectral analysis showed no changes in the structure of the main and side polyurethane chains. Both mechanical and spectral tests prove that polyurethanes processed using 3D printing technology can be widely used in mining. Research limitations/implications: Only one type of TPU was processed in this work. Further work should show that synthetic mine water does not degrade the mechanical properties of other commercially available TPUs. Practical implications: The additive technology allows getting elements of mining clothing, ortheses, insoles or exoskeleton elements adapted to one miner. Originality/value: The conducted tests allowed to determine no deterioration of the mechanical properties of samples aged in synthetic mine water. TPU processing using 3D printing technology can be used in mining.


2008 ◽  
Vol 47-50 ◽  
pp. 592-595 ◽  
Author(s):  
Ming Hwa R. Jen ◽  
Yi Chun Sung ◽  
Yin Da Lai

To deal with the stringent operational demands the aerospace structural materials of light weight Aluminum alloy 2024 sheets and plies of carbon fibers reinforced thermoplastic matrix PEEK were used to sustain at least 80% of their mechanical properties at elevated temperature. The addition of nanoparticles SiO2 can enhance the composite laminate strength and stiffness. Also, Al 2024 sheets were treated by an anodic method of electroplating to increase surface roughness to achieve perfectly bonding with matrix PEEK. Then, the modified diaphragm curing process was adopted to make the innovative hybrid Al/APC-2 hybrid nanocomposite laminates. Next, both static tensile and fatigue tests were conducted at elevated temperature to obtain the mechanical properties, lives and failure mechanisms to verify the improved features of hybrid specimens. From tensile tests the mechanical properties of Al/APC-2 [4Al/0/±45/90/2Al]s hybrid laminates at elevated temperature were obtained. Although there is a big drop at 150°C, the reduction in strength from RT to 125°C is generally not significant. The longitudinal stiffness is almost unchanged at elevated temperature. After cyclic tension-tension (T-T) tests, the positions of received S-N curves go downwards as temperature rising. No delaminations were found in both tests. If the applied stress normalized by the ultimate strength at corresponding temperature, the normalized S-N curves are closer with some curve positions reversed. Significant improvement of manufacturing and enhancement of mechanical properties in hybrid laminates were achieved finally.


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