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Article
Publication date: 13 October 2020

Eduardo Cuesta, Braulio J. Alvarez, Pablo Zapico and Sara Giganto

This study aims to analyze the effect of the different common post-processes on the geometrical and dimensional accuracy of selective laser melting (SLM) parts.

Abstract

Purpose

This study aims to analyze the effect of the different common post-processes on the geometrical and dimensional accuracy of selective laser melting (SLM) parts.

Design/methodology/approach

An artefact has been designed including cubic features formed by planar surfaces orientated according to the machine axes, covering all the X-Y area of the working space. The artefact has been analyzed both geometrically (flatness, parallelism) and dimensionally (sizes, distances) from coordinate measuring machine measurement results at three stages, namely, as-built, after sand-blasting and after stress-relieving heat treatment.

Findings

Results from the SLM machine used in this study lead to smaller parts than the nominal ones. This effect depends on the direction of the evaluated dimension of the parts, i.e. X, Y or Z direction and is differently affected by the sandblasting post-process (average erosion ratio of 68, 54 and 9 µm, respectively), being practically unaltered by the HT applied after.

Originality/value

This paper shows the influence, from a geometric and dimensional point of view, of two of the most common post-processes used after producing SLM parts, such as sand-blasting and stress-relieving heat treatment, that have not been considered in previous research.

Details

Rapid Prototyping Journal, vol. 26 no. 10
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 1 August 1998

G. Batis, N. Kouloumbi and E. Soulis

The aim of the present work was to compare the performance of two coating systems applied on steel specimens. The first of them demands sandblasting pretreatment of the…

Abstract

The aim of the present work was to compare the performance of two coating systems applied on steel specimens. The first of them demands sandblasting pretreatment of the metal surface while the second one, which does not need it, leads to rust transformation. These systems were examined in three corrosive environments i.e. a geothermal fluid of low enthalpy, a 3.5 wt per cent NaCl solution and a 5wt per cent NaCl in a salt spray cabinet. The anticorrosive capability of the two coating systems was evaluated at predetermined exposure times by mass loss measurements of the steel substrate, by potentiodynamic polarization curves and by the half‐cell potential time evolution. Visual examination of the degree of rusting and blistering was also carried out. The results indicate that both coating systems exhibit almost similar protective behavior under the same conditions of pretreatment. In all cases, the corrosion rate increases with the increase of the surface roughness.

Details

Anti-Corrosion Methods and Materials, vol. 45 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 1 January 1991

Anna Kochan

A robotic solution is helping French railways (SNCF) to maintain the armatures of its electric traction engines. During its working life of 20–25 years, a normal SNCF…

Abstract

A robotic solution is helping French railways (SNCF) to maintain the armatures of its electric traction engines. During its working life of 20–25 years, a normal SNCF traction engine covers a distance of 6–7 million kilometres. While in service the engine undergoes regular inspection and examination. Should one of these periodic tests reveal unacceptable results relating to the dimensions of the dielectrics, the armature must be unwound and repaired. As part of the repair process, the tiny spaces between the hundreds of commutator strips around the armature, onto which the windings are soldered, have to be cleaned. The cleaning of these commutator strips is a delicate job which has to be performed with meticulous detail by sand blasting with corundum or aluminium oxide. The task has been previously performed manually but was found to be very difficult and extremely costly in terms of labour.

Details

Industrial Robot: An International Journal, vol. 18 no. 1
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 1 March 1991

M. Lahdenperä

In this research work thick‐film manufacturing technology on stainless steel baseplates was developed. Adequate adhesion of dielectric IP211 to the steel substrate was…

Abstract

In this research work thick‐film manufacturing technology on stainless steel baseplates was developed. Adequate adhesion of dielectric IP211 to the steel substrate was achieved only by sand blast roughening. Standard PdAg thick‐film conductors were not solderable to IP211. The solution was to have a separate multilayer dielectric under conductors to be soldered. The reliability of soft soldering and gold wire bonding of thick‐film metallisation on stainless steel and other baseplate materials was evaluated. The technology developed was applied to manufacturing an intelligent signal node. Present expertise enables the manufacture of thick‐film hybrids on stainless steel baseplates. Development of an industrial production line would, however, involve considerable effort.

Details

Microelectronics International, vol. 8 no. 3
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 1 April 1954

E. Knuth‐Winterfeldt, H. Bjerring Andersen, J.E.O. Mayne, Hans Arup, J.L. Mansa, H. Nord, J.L. Mansa, J. Bjerrum and Arne Jeppesen

In the Scandinavian countries there is growing awareness of the need to intensify the fight against corrosion by co‐operative research and the exchange of information…

Abstract

In the Scandinavian countries there is growing awareness of the need to intensify the fight against corrosion by co‐operative research and the exchange of information. This culminated in the Scandinavian Corrosion Con‐ference held in Copenhagen last month. A number of papers were presented, mostly by Danish scientists. There was also a contribution by a British scientist. Here are summaries of these papers, specially translated and prepared for CORROSION TECHNOLOGY.

Details

Anti-Corrosion Methods and Materials, vol. 1 no. 4
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 3 April 2019

Jashanpreet Singh, Satish Kumar and S.K. Mohapatra

This study/paper aims to investigate the erosion wear performance of Ni-based coatings [Ni-Cr-O and NiCrBSiFe-WC(Co)] under sand-water slurry conditions.

Abstract

Purpose

This study/paper aims to investigate the erosion wear performance of Ni-based coatings [Ni-Cr-O and NiCrBSiFe-WC(Co)] under sand-water slurry conditions.

Design/methodology/approach

A high-velocity oxy-fuel (HVOF) process was used to deposit the Ni-based coatings [Ni-Cr-O and NiCrBSiFe-WC(Co)] on the surface of stainless steel (SS 316L) substrate. A Ducom TR-41 erosion tester was used to conduct the tribological experiments on bare/HVOF coated SS 316L. The erosion wear experiments were carried out for different time durations (1.30-3.00 h) at different impact angles (0-60°) by running the pot tester at different rotational speeds (600-1,500 rev/min). The solid concentration of sand slurry was taken in the range of 30-60 Wt.%. The surface roughness of Ni-based coated surfaces was also measured along the transverse length of the specimens.

Findings

Results show the arithmetic mean roughness (Ra) values of Ni-Cr-O and NiCrBSiFe-WC coated SS-316L were 7.04 and 6.67 µm, respectively. The erosion wear SS-316L was almost 3.5 ± 1.5 times greater than that of the NiCrBSiFe-WC coatings. NiBCrSi-WC(Co) sprayed SS-316L showed lower erosion wear than Ni-Cr-O sprayed SS-316L. Microscopically, the eroded Ni-Cr-O coating underwent plowing, microcutting and craters. Ni-Cr-O coating have shown the ductile nature of erosion wear mechanism. NiBCrSi-WC(Co) surface underwent craters, plowing, carbide/boride pullout, fractures and intact. Erosion wear mechanisms on the eroded surface of NiBCrSi-WC(Co) were neither purely ductile nor brittle.

Practical implications

It is a useful technique to estimate the erosion wear of hydraulic machinery coated with Ni-based coatings imposed under mining conditions.

Originality/value

The erosion wear performance of HVOF-sprayed Ni-Cr-O and NiCrBSiFe-WC(Co) powders was investigated through extensive experimentation, and the results are well supported by scanning electron micrographs and 3D topology.

Details

Industrial Lubrication and Tribology, vol. 71 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 1 May 1989

The new draft British Stanard 88/44568 for fusion bonded epoxy coated rebar, currently manufactured in the UK only by Allied Bar Coaters, is the first such specification…

Abstract

The new draft British Stanard 88/44568 for fusion bonded epoxy coated rebar, currently manufactured in the UK only by Allied Bar Coaters, is the first such specification in Europe. The aim of the draft standard is to set a higher standard of manufacture for a product whose only available specification was the American ASTM A775 standard. This means that engineers will now be able to specify a product specially designed for the more demanding requirements of the European market.

Details

Pigment & Resin Technology, vol. 18 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 4 February 2014

A.B. Hazar Yoruç, O. Elkoca, Harika Ekşioğlu Yıldız and Ahmet Koyun

The purpose of this paper is to investigate the effect of blasting treatment with zirconia/hydroxyapatite powders on the surface roughness, in vitro bioactivity and wear…

Abstract

Purpose

The purpose of this paper is to investigate the effect of blasting treatment with zirconia/hydroxyapatite powders on the surface roughness, in vitro bioactivity and wear behavior of Ti6Al4V alloy (Grade V).

Design/methodology/approach

Ti6Al4V specimens were sandblasted with ZrO2 and HA [Ca10(PO4)6(OH)2] powders in a commercial blasting cabinet. Surface analysis was performed evaluating eroded surfaces by scanning electron microscopy. Roughness surface analysis of the samples was performed with a surface roughness tester and in vitro bioactivity of titanium surfaces was examined in the simulated body fluid (SBF) solution before and after blasting. Wear resistance is evaluated by the weight loss during the test.

Findings

The highest value of surface roughness is obtained with a mixture of 25 percent ZrO2+75 percent HA (Z25). Z25 exhibited also lower weight loss than Ti6Al4V and other treated samples. These results indicate that surface treatment with 25 percent ZrO2+75 percent HA provides the highest amount of HA adhesion on the surface of Ti6Al4V implant. Finally, the sample surfaces were contacted with SBF solutions for seven days, and Ca/P accumulation was identified on the blasted surfaces. ZrO2/HA blasting method can be used to improve the wear characteristics and the biocompatibility of the implant materials.

Originality/value

The paper provides information about the effect of ZrO2/HA blasting treatment on the surface properties, in vitro bioactivity and wear behavior of Ti6Al4V implant materials.

Details

Industrial Lubrication and Tribology, vol. 66 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 1 October 1957

J.C. Hudson

Recherches sur la Corrosion de la British Iron and Steel Research Association.

Abstract

Recherches sur la Corrosion de la British Iron and Steel Research Association.

Details

Anti-Corrosion Methods and Materials, vol. 4 no. 10
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 December 1973

R.N. Washburn

Eight years of testing and excellent field results confirm that paints made with Primal MV‐1 acrylic emulsion offer metal surfaces outstanding protection against corrosion.

Abstract

Eight years of testing and excellent field results confirm that paints made with Primal MV‐1 acrylic emulsion offer metal surfaces outstanding protection against corrosion.

Details

Pigment & Resin Technology, vol. 2 no. 12
Type: Research Article
ISSN: 0369-9420

1 – 10 of 217