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Article
Publication date: 16 August 2011

Mumin Sahin and Ceyhun Sevil

The aim is to provide detailed mechanical and metallurgical examinations of ion‐nitrided austenitic‐stainless steels.

Abstract

Purpose

The aim is to provide detailed mechanical and metallurgical examinations of ion‐nitrided austenitic‐stainless steels.

Design/methodology/approach

Austenitic‐stainless steel was the material chosen for the present study. Ion nitriding process was applied to fatigue and tensile samples prepared by machining. Process temperature was 550°C and treatment time period 24 and 60 h. Then, tensile, fatigue, notch‐impact, hardness tests were applied and metallographic examinations were performed.

Findings

High temperature and longer treatment by ion nitriding decreased fatigue and tensile strengths together with notch‐impact toughness. Scanning electron microscopy and energy dispersive X‐ray spectroscopy analysis revealed formation of nitrides on the sample surfaces. Surface hardness increased with an increase in process time due to diffusion of nitrogen during ion nitriding.

Research limitations/implications

It would be interesting to search the different temperature and time intervals of the ion nitriding. It could be a good idea if future work could be concentrated on ion nitriding on welded stainless steels.

Practical implications

Surfaces of mechanical parts are exposed to higher stress and abrasive forces compared to inside mechanical parts during the time period that mechanical components carry out their expected functions. When stresses and forces exceed the surface strength limit of the material, cracks begin to form at the material surface leading to abrasion and corrosion. Therefore, surface strength of materials needs to be increased to provide a longer service life. Ion (plasma) nitriding is a possible remedy for surface wear.

Originality/value

The main value of this paper is to contribute and fulfil the detailed mechanical and metallurgical examinations of ion‐nitrided austenitic‐stainless steels that are being studied so far in the literature.

Details

Industrial Lubrication and Tribology, vol. 63 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 20 June 2017

Shiqing Cao, Dandan Yu, Weilan Xue, Zuoxiang Zeng and Wanyu Zhu

The purpose of this paper is to prepare a new modified polybutylene terephalate (MPBT) for fused deposition modeling (FDM) to increase the variety of materials compatible…

Abstract

Purpose

The purpose of this paper is to prepare a new modified polybutylene terephalate (MPBT) for fused deposition modeling (FDM) to increase the variety of materials compatible with printing. And the printing materials can be used to print components with a complex structure and functional mechanical parts.

Design/methodology/approach

The MPBT, poly(butylene terephalate-co-isophthalate-co-sebacate) (PBTIS), was prepared for FDM by direct esterification and subsequent polycondensation using terephthalic acid (PTA), isophthalic acid (PIA), sebacic acid (SA) and 1,4-butanediol (BDO). The effects of the content of PIA (20-40 mol%) on the mechanical properties of PBTIS were investigated when the mole per cent of SA (αSA) is zero. The effects of αSA (0-7mol%) on the thermal, rheological and mechanical properties of PBTIS were investigated at nPTA/nPIA = 7/3. A desktop wire drawing and extruding machine was used to fabricate the filaments, whose printability and anisotropy were tested by three-dimensional (3D) printing experiments.

Findings

A candidate content of PIA introducing into PBT was obtained to be about 30 per cent, and the Izod notched impact strength of PBTIS increased with the increase of αSA. The results showed that the PBTIS (nPTA/nPIA = 7/3, αSA = 3-5mol%) is suitable for FDM.

Originality/value

New printing materials with good Izod notched impact strength were obtained by introducing PIA and SA (nPTA/nPIA = 7/3, αSA = 3-5 mol%) into PBT and their anisotropy are better than that of ABS.

Details

Rapid Prototyping Journal, vol. 23 no. 4
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 20 March 2017

Stephen Oluwashola Akande, Kenny Dalgarno and Javier Munguia

The purpose of this research is to determine what tests can be most useful in quality assurance and control when using fused filament fabrication (FFF) 3D printing…

Abstract

Purpose

The purpose of this research is to determine what tests can be most useful in quality assurance and control when using fused filament fabrication (FFF) 3D printing machines. The quality of the bond between layers is critical for the structural integrity of the fused filament fabricated parts.

Design/methodology/approach

Therefore, to determine the influence of process parameters on the quality of parts’ tensile, flexural, notched and un-notched impact, test specimens were fabricated in polylactic acid (PLA) using FFF with different layer thicknesses, fill densities, orientation and print speeds. The mechanical properties were then assessed along with the accuracy and mass of the samples.

Findings

It is concluded that a notched impact test gives a measure of interlayer bond strength which can be used across build styles to track machine performance, and that this, together with the mass and dimensions of the impact-test specimens, offers an appropriate set of tests capable of tracking the mechanical properties of parts produced using the FFF technique.

Originality/value

Therefore, this research finding will be of value in benchmarking FFF machines for quality parts fabrications.

Details

Rapid Prototyping Journal, vol. 23 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 3 April 2019

Josef Valentin Ecker, Andreas Haider, Ivana Burzic, Axel Huber, Gerhard Eder and Sabine Hild

This papers aims to study the influence of water absorption on the mechanical properties of poly lactic acid (PLA) and PLA/Wood composites. Virgin PLA and PLA/Wood…

968

Abstract

Purpose

This papers aims to study the influence of water absorption on the mechanical properties of poly lactic acid (PLA) and PLA/Wood composites. Virgin PLA and PLA/Wood double-bone-shaped specimens were prepared by two methods: injection moulding and 3D printing. The results were compared to each other and showed the influence of the production method on the properties of the produced parts.

Design/methodology/approach

Morphology studies were done by scanning electron microscopy (SEM) from fracture surfaces of tensile and notched impact specimens of all samples. Tensile properties were analysed by the production and testing of dog-bone-shaped samples. Heat deflection temperature (HDT) was tested, as also was the crystallinity of the tested samples by differential scanning calorimetry.

Findings

The values for notched impact strength were higher upon water uptake in the case of injection-moulded specimens, which was not the case with 3D-printed specimens. Tensile properties of the specimens produced by both methods were reduced after water absorption tests. Values of the HDT were also lower after water absorption tests studied for both processing methods.

Originality/value

Morphology studies were done by SEM from fracture surfaces of tensile as well as notched impact specimens of injection-moulded and 3D-printed samples. The effect of water storage on various samples was tested. The two different production technologies were compared to each other owing to their influence of water storage. This study also dealt with NFC compounds and produced NFC composites and the influence of water storage on these samples.

Details

Rapid Prototyping Journal, vol. 25 no. 4
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 April 2004

Mümin Sahin and H. Erol Akata

In the presented study, AISI 1040 medium carbon steel and AISI 304 austenitic stainless steel parts were joined by friction welding. The welding process was carried out…

3967

Abstract

In the presented study, AISI 1040 medium carbon steel and AISI 304 austenitic stainless steel parts were joined by friction welding. The welding process was carried out under optimized conditions using statistical approach. Tension tests were applied to welded parts to obtain the strength of the joints. Fatigue properties were additionally obtained experimentally under fluctuated tensile loads. Finally, notch impact tests were applied to the joints. Microstructures using microphotographs were examined in the heat affected zone of welded parts. Hardness variations in welding zone were also obtained. Experimental results were compared with those of previous studies.

Details

Industrial Lubrication and Tribology, vol. 56 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 4 March 2014

Mumin Sahin

The main purpose of the present study was to evaluate the metallurgical and mechanical properties of dissimilar metal friction welds (FWs) between aluminium and type 304…

Abstract

Purpose

The main purpose of the present study was to evaluate the metallurgical and mechanical properties of dissimilar metal friction welds (FWs) between aluminium and type 304 stainless steel.

Design/methodology/approach

One of the manufacturing methods used to produce parts made from different materials is the FW method. Therefore, in the present study, austenitic stainless steel and aluminium parts were joined by FW. Tensile, fatigue and notch-impact tests were applied to FW specimens, and the results were compared with those for the original materials. Microstructure, energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis and hardness variations were conducted on the joints.

Findings

It was found from the microstructure and XRD analysis that inter-metallic phases formed in the interface which further caused a decrease in the strength of the joints.

Research limitations/implications

In this study, the rotation speed was kept constant. The effects of the rotation speed on the welding quality can be examined in future. It is important to note that the FW process was successfully accomplished in this study although it was particularly difficult to obtain the weld due to the large deformations at the interface.

Practical implications

Low-density components such as aluminium and magnesium can be joined with steels owing to being cost-effective in industry. Application of classical welding techniques to such materials is difficult because they have different thermal properties. Their welding plays a key part in industrial quality and process control, in the efficient use of energy and other resources, in health and safety. Then, this study will contribute for welded, brazed and soldered materials.

Originality/value

The main value of this paper is to contribute and fulfill the influence of the interface on properties in welding of various materials that is being studied so far in the literature.

Details

Industrial Lubrication and Tribology, vol. 66 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 January 2008

W. Tan, Z.Y. Liu, D. Wu and G.D. Wang

In the present paper, a modeling for the energy absorption (CVN) at room temperature of hot‐rolled plates in Charpy V‐notch impact tests was investigated, in which an…

Abstract

In the present paper, a modeling for the energy absorption (CVN) at room temperature of hot‐rolled plates in Charpy V‐notch impact tests was investigated, in which an BP(Back Propagation) ANN (Artificial Neural Network) model with three layers was developed to take into considerations chemical compositions, processing parameters, yield strength, tensile strength and product thickness. The measured or predicted strength values have been used to predict the energy absorption in Charpy impact tests, both showing good agreements with the measured values. In order to compare the precision of the neural‐network methods in predicting CVN, linear regression analysis was performed by using the same data. Also, analyses were made for the effects of alloying elements, microstructure and processing parameters on CVN using ANN model, being consistent with the metallurgical rules. It concluded that the absorbed energy in Charpy impact tests for given steel compositions, processing parameters, strengths and plate thickness can be predicted by using the modeling.

Details

Multidiscipline Modeling in Materials and Structures, vol. 4 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 3 July 2017

Baolong Wang, Haiqing Ma, Di Wu, Lien Zhu and Zheng Jin

The purpose of this paper is to prepare new modified polypropylene (PP) with phenolic microspheres (PFMs). Furthermore, the crystallinity and mechanical properties of PP…

Abstract

Purpose

The purpose of this paper is to prepare new modified polypropylene (PP) with phenolic microspheres (PFMs). Furthermore, the crystallinity and mechanical properties of PP modified by fillers (silicon dioxide [SiO2] and light calcium carbonate [CaCO3], respectively) have also been investigated and compared.

Design/methodology/approach

For effective toughening, three different fillers were added into the PP matrix. PP composites were prepared through melt blending with double-screw extruder and injection moulding machine.

Findings

It was found that with the addition of 3 Wt.% PFM, the impact strength was maximum in all PP composites and increased by 1.4 times compared to pure PP. Scanning electron microscopy (SEM) and polarised optical microscopy (POM) analysis confirmed that 3 Wt.% PFM, 3 Wt.% SiO2 and 2 Wt.% CaCO3 were optimal to add in PP and PFM to give the best compatibility with PP.

Research limitations/implications

PFM particles not only are tougher and less brittle and can offer other advantages such as enhanced machinability, but also are important organic materials and have a good compatibility with polymer for reinforcing polymer properties.

Practical implications

The method developed provided a simple and practical solution to improving the toughness of PP.

Social implications

There will be thermoplastic plastics with higher toughness in domestic, packaging and automotive applications, particularly at lower temperatures.

Originality/value

The PP modified by tiny amounts of fillers in this work had high toughness, which can be applied as an efficient material widely used in domestic, packaging and automotive applications.

Details

Pigment & Resin Technology, vol. 46 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 5 October 2015

Halil Ibrahim Ünal, Hakan Atapek, Baran Gürkan Beleli, Seyda Polat, Serap Gümüs and Ersoy Erisir

The purpose of this paper is to investigate the fracture of grade X42 microalloyed steel used as pipe material after tensile test at room temperature and impact tests at…

Abstract

Purpose

The purpose of this paper is to investigate the fracture of grade X42 microalloyed steel used as pipe material after tensile test at room temperature and impact tests at 0, −20 and −40°C, respectively.

Design/methodology/approach

In the first stage of the study, X42 steels in the form of sheet and pipe materials were selected and etched samples were characterized using light microscope. In the second stage, mechanical properties of steels were obtained by microhardness measurements, static tensile and impact tests and all the broken surfaces were examined by scanning electron microscope to determine the fracture type as a function of both microstructure and loading.

Findings

The examinations revealed that: first, the sheet material had a typical ferritic-pearlitic matrix, second, the transverse section of the sheet steel exhibited a matrix consisting of polygonal ferrite-aligned pearlite colonies and the longitudinal one had elongated ferrite phase and pearlite colonies in the direction of rolling, third, ferrite and pearlite distribution was different from the sheet material due to multiaxial deformation in the pipe material, fourth, tensile fracture surfaces of the steels had typical dimple fracture induced by microvoid coalescence, fifth, impact fracture surfaces of the steels changed as a function of the test temperature and cleavage fracture mode of ferritic-pearlitic matrix became more dominant as the temperature decreased, and sixth, grain morphology had an effect on the fracture behavior of the steels.

Originality/value

The paper explains the fracture behaviour of X42 microalloyed pipeline steel and its fractographical analysis.

Details

International Journal of Structural Integrity, vol. 6 no. 5
Type: Research Article
ISSN: 1757-9864

Keywords

Content available
Article
Publication date: 1 February 1999

158

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 71 no. 1
Type: Research Article
ISSN: 0002-2667

Keywords

1 – 10 of 44