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Article
Publication date: 16 October 2018

Mingkang Zhang, Yongqiang Yang, Changhui Song, Yuchao Bai and Zefeng Xiao

This study aims to focus on the heat treatment influence on the corrosion resistance, adhesion of Streptococcus mutans and mechanical properties of CoCrMo alloys manufactured by…

566

Abstract

Purpose

This study aims to focus on the heat treatment influence on the corrosion resistance, adhesion of Streptococcus mutans and mechanical properties of CoCrMo alloys manufactured by the selective laser melting (SLM).

Design/methodology/approach

CoCrMo alloys were manufactured using the Dimetal-100 machine. X-ray diffraction (XRD), metallographic analysis, scanning electron microscopy (SEM), electrochemical corrosion, Vickers microhardness and tensile tests were used to characterize SLM-produced CoCrMo alloys and compare them with the ones manufactured by casting and with the ASTM F75 standard.

Findings

The electrochemical results showed that SLM900 samples had the best corrosion resistance in artificial saliva. The adhesion results showed least propagation and overall quantity of Streptococcus mutans on the SLM900 sample. The microhardness, tensile and yield strength of As-SLM, SLM900 and SLM1200D samples were measured according to the ASTM F75 standard. The elongation of SLM900 was less than 8 per cent, which does not meet the standard specifications. Analysis of the fracture morphology showed that the fracture mechanisms of As-SLM and SLM1200D belong to the quasi-cleavage fracture type, and the mechanical fracture mechanism of SLM900 can be characterized as brittle fracture.

Originality/value

This paper presents the adhesion properties of Streptococcus mutans on the surface of CoCrMo alloys manufactured by SLM and proposes how to regulate the effect of the heat treatment on the corrosion resistance and mechanical properties of CoCrMo alloys manufactured by SLM.

Details

Rapid Prototyping Journal, vol. 24 no. 7
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 9 April 2018

Zefeng Xiao, Yongqiang Yang, Di Wang, Changhui Song and Yuchao Bai

This paper aims to summarize design rules based on the process characteristics of selective laser melting (SLM) and structural optimization and apply the design rules in the…

574

Abstract

Purpose

This paper aims to summarize design rules based on the process characteristics of selective laser melting (SLM) and structural optimization and apply the design rules in the lightweight design of an aluminum alloy antenna bracket. The design goal is to reduce 30 per cent of the weight while maintaining the stress levels in the original part.

Design/methodology/approach

To reduce weight as much as possible, the titanium alloy with higher specific strength was selected during the process of optimization. The material distribution of the bracket was improved by the topology optimization design. The redesign for SLM was used to obtain an optimization model, which was more suitable for SLM. The component performance was improved by shape optimization. The modal analysis data of the structural optimization model were compared with those of the stochastic lightweight model to verify the structural optimization model. The scanning data were compared with those of the original model to verify whether the model was suitable for SLM.

Findings

Structural optimization design for antenna bracket realized the mass decrease of 30.43 per cent and the fundamental frequency increase of 50.18 per cent. The modal analysis data of the stochastic lightweight model and the structural optimization model indicated that the optimization performance of structural optimization method was better than that of the stochastic lightweight method. The comparison results between the scanning data of the forming part and the original data confirmed that the structural optimization design for SLM lightweight component could achieve the desired forming accuracy.

Originality/value

This paper summarizes geometric constraints in SLM and derives design rules of structural optimization based on the process characteristics of SLM. SLM design rules make structural optimization design more reasonable. The combination of structural optimization design and SLM can improve the performance of lightweight antenna bracket significantly.

Details

Rapid Prototyping Journal, vol. 24 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 9 April 2018

Yuchao Bai, Yongqiang Yang, Zefeng Xiao and Di Wang

This paper aims to verify whether selective laser melting (SLM) could be used for manufacturing mold with conformal cooling channels and determine whether the mechanical…

814

Abstract

Purpose

This paper aims to verify whether selective laser melting (SLM) could be used for manufacturing mold with conformal cooling channels and determine whether the mechanical properties development of SLM manufacturing maraging steel mold would be beneficial to improve the quality of mold.

Design/methodology/approach

A series of block specimens and cylindrical tensile specimens are manufactured by SLM, and then are heat treated by solution treatment (ST) and solution treatment + aging treatment (ST + AT), respectively. The development of microstructure, microhardness and tensile strength of specimens is investigated. Then, a mold with conformal cooling channels is designed and manufactured by SLM and machined after ST with microhardness decreasing.

Findings

The morphology of microstructure varies widely under different heat treatment. The microhardness and tensile strength decrease after ST with cellular structure broken, which is conducive to mechanical finishing for mold to improve surface accuracy. After that, the hardness and strength of the mold increase significantly by AT with the precipitation of Ni3Mo, Fe2Mo and Ni3Ti particles. The maraging steel mold with conformal cooling channels can be manufactured by SLM successfully. And the surface accuracy of mold could be improved easily by machining.

Originality/value

Compared with the traditional mold with simple cooling channels, the mold with conformal cooling channels can be manufactured by SLM directly. The hardness of maraging steel mold manufactured by SLM can be reduced through ST, which is conducive to mechanical finishing for overcoming the defect of low precision of SLM directly manufacturing mold. This provides a new way for manufacturing mold of high quality.

Details

Rapid Prototyping Journal, vol. 24 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

Available. Open Access. Open Access
Article
Publication date: 22 September 2022

Christian Gomes-e-Souza Munaier, Fernando Rejani Miyazaki and José Afonso Mazzon

This study aims to evaluate the impact of a sustainable production action on consumer trust and purchase intention by a company involved in moral transgression and also analyze…

1871

Abstract

Purpose

This study aims to evaluate the impact of a sustainable production action on consumer trust and purchase intention by a company involved in moral transgression and also analyze the effect on consumer trust and purchase intention if a company, after green marketing, is identified as greenwashing spreader.

Design/methodology/approach

This quantitative nature (n = 121) study uses scale’s discriminant and convergent validity analyses, structural equation modeling and Student’s t-test.

Findings

Even for previously morally transgressive brands, actions of social legitimation, such as embracing environmental causes, positively impact consumer trust and purchase intention. However, consumers drop brand trust and purchase intention when verifying that this action was greenwashing.

Research limitations/implications

Mediating or moderating variables of ecological awareness, such as religiosity or political view, were not tested.

Practical implications

This article combines the impact of positive, sustainable management actions for morally transgressive companies and the effects of new transgression on their sustainable management action. Thus, it aims to reduce the gap between organizational practice and management research.

Social implications

This article shows that embracing society’s emerging causes and helping the world be a better place to live, moving toward the 2030 United Nations agenda, have practical repercussions for organizations.

Originality/value

This article contributes both to the literature and managerial implications by combining the impact of positive, sustainable management actions for morally transgressive companies and the effects of new transgression on their sustainable management action, thus reducing the gap between management research and organizational practice by unveiling the relations between sustainable actions and their perceived consequences.

Details

RAUSP Management Journal, vol. 57 no. 4
Type: Research Article
ISSN: 2531-0488

Keywords

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