Interview with Emma Molobi on Additive Manufacturing for Railway Infrastructure

Emma Molobi

3D printing and additive manufacturing are becoming important tools in the engineering sector. One nascent development is occurring in the railway sector which is trying to utilise the technology to improve the railway infrastructure. In this interview, Emma Molobi describes the importance of Additive manufacturing and also making reference to the railway industry.

What is your experience with AM? 

3D printing has become a revolutionary manufacturing technology that has changed the way products are designed and manufactured. AM is described as a disruptive manufacturing technology because it offers a new blueprint which will alter traditional methods of metal manufacturing such as casting, molding, machining, welding and forging practices to name a few.

AM has existed in various levels of sophistication for decades now however, the buzz around this technology has recently been re-fuelled especially in the metal industry and this has been due to its advantages namely: the production of near net-shaped components which require no additional cutting, shorter manufacturing turnaround times, production of customized and intricately shaped components. Compared to conventional manufacturing methods such as casting and molding processes AM technologies do not require fabrication patterns thus leading to production cost savings. The use of AM in the industry can become a gateway not only into the metal manufacturing fraternity but also the refurbishment and reconditioning of components that have reached their operational life-cycle. I am personally involved in the usage of the Laser Engineered Net Shaping (LENS) technology, which is an AM process that uses powder as the feedstock material which is directly deposited onto a substrate. The heat from a laser source is used to melt the powder in a layer by layer process and thus rapidly forming a 3D component upon cooling.

This process can be used in the manufacture and repair of a wide range of materials such as stainless steels, tool steels, nickel, cobalt and titanium alloys. The use of lasers as a heat source has an advantage of low heat inputs which is important during refurbishment processes, thus ensuring that the metallurgical integrity of the original component is not altered.

The LENS machine by Optomec

 As a Senior Metallurgical Engineer at Transnet Engineering, how has the organization adopted 3D printing and Additive Manufacturing in its operations?

Railway industries form the backbone of industrialization where infrastructures and industrial hubs are built. Innovative maintenance and efficiency improvements are some of the rail specific benefits of industry 4.0. Also, Africa’s railway infrastructure aims to establish an intercontinental rail and pipeline link that will promote intra-African trade. This expansion concept requires manufacturing processes that yield good integrity components with high throughput, at the shortest turn-around time.

Additive manufacturing in the railway industry in South Africa is still under research and development, its adoption is mainly in the aerospace industry. However, the integration of conventional and advanced manufacturing technologies in the form of hybrid processes is under review and investigation into whether mass production will be feasible. The blueprint for the future railway, port, and pipeline system lies in the concepts of industry 4.0, which is inclusive of additive manufacturing.

Inside the LENS® machine during deposition

You are a member of Women in 3D printing. Can you describe the organization and its impact on 3D printing and additive manufacturing?

Women in 3D printing is a non-profit organization that aims to promote and support women in the AM industry. The mission is to increase the visibility of women and to encourage the involvement of women in 3D printing technologies.

My role as a woman in additive manufacturing is to promote and create awareness within the engineering arena in South Africa. Early this year I presented at the Laser Technology Conference to create an awareness of the role and benefits of lasers in industry 4.0.  Smart manufacturing is a concept of industry 4.0 which encompasses AM technologies. For Africa and the rest of the world to fully realize the concepts of industry 4.0 we need collaboration between people of different genders, races, and backgrounds to ensure equal representation.

The involvement of women in the AM arena will increase women in the workforce and widen the economic gender gap. In 2018 I presented at the 8^th Annual Women in Engineering Convention in South Africa, Johannesburg and it was quite clear that we need the involvement of more women in AM to diversify the industry. Currently, the participation of women in AM is a niche as this technology still needs to be fully commercialized.

From your perspective, what significant role are 3D printing and Additive manufacturing playing in Research and Development?

 AM technologies such as Laser Engineered Net Shaping (LENS) have successfully been applied to a wide range of materials. The advantages of AM over conventional manufacturing technologies has sparked interest in the hard metal industry even though this process has not been commercialized yet.

Hard metals have found ubiquitous usage in industrial sectors such as the mining, automotive, aerospace, petrochemical, and the steelmaking industry. This has led to an increase in the demand and production of hard metals namely tungsten-based hard metals globally. There is still a considerable amount of research required to provide a fundamental scientific understanding of manufacturing hard metals using AM processes such as the LENS® technology. The use of AM in the hard metal industry can be beneficial in overcoming the disadvantages posed by conventional manufacturing methods which include: longer production times, the use of additional fixtures and patterns which will lead to the increased cost of production.

I am currently pursuing a Ph.D. with the University of the Witwatersrand into AM in the hard metal industry.  This research is funded by the South Africa Department of Science and Technology (DST) and National Research Foundation (NRF), Centre of Excellence in Strong Materials. In collaboration with the Council of Scientific and Industrial Research (CSIR), within the National Laser Centre (NLC), the research will provide a scientific and economic contribution to the feasibility of using AM technologies to manufacture hard-metal components and also drive the commercialization aspect in South Africa.