EPSRC Industrial Case Studentship 

TWI Ltd, Cambridge and Brunel University, Uxbridge

Duration: 3.5 years

Start Date: 2012/2013 academic year

Improved brazing processes for joining ceramics to metals

Project

The properties of ceramics make them a highly attractive industrial material, particularly in severe operating conditions. In order to get the most out of them it is a common requirement to join them to metals. Whilst this can be done in many ways, the preferred industrial method is often brazing, since this gives high strength, reliable joints. However, it introduces two problems, wetting and mismatch in coefficient of thermal expansion (CTE).

Normal 0 false false false EN-GB X-NONE X-NONE In order to form a good bond, it is necessary for the braze filler metal to wet to the surfaces of both the metal and the ceramic. Brazing uses a liquid metal to form the bond, which naturally wets well to the metallic surface, but the ceramic surface usually needs pre-treatment or the use of specialist braze fillers. In order to melt the metallic filler, brazing is conducted at high temperature (>450degC) and typically in vacuum. As most ceramics have a much lower CTE than metals, on cooling down after brazing, stress is generated in the joint which can lead to cracking and premature failure of the joint.

This project aims to build on existing knowledge in this field by developing a fundamental understanding of the ways in which the braze filler interacts with the ceramic and metallic surfaces at the molecular level. Control over reactive metal activity and understanding the chemical and physical nature of the joint/interface layer is critical. It will involve both theoretical and experimental aspects, including the use of bulk analytical techniques such as calorimetry, practical trials with vacuum brazing furnaces and subsequent microstructural and micro/nano hardness characterisation of the interface by electron microscopy and surface analysis techniques.

This groundbreaking research will aid understanding of way in which the braze filler metal reacts with the ceramic and metal surfaces during the brazing process. It is anticipated that this fundamental understanding will allow the development of improved brazing processes for joining ceramics to metals.

Supervisors: The project will be jointly supervised by Brunel University and TWI Ltd.  The academic supervisor will be Dr N. Hari Babu and the industrial supervisor will be Nicholas Ludford. The student will have access to the state of the art facilities at both TWI Ltd and the University. The costs of subsistence and travel between locations will be covered by the studentship.

Professional Development: Brunel Graduate School supports all postgraduates through the provision of a comprehensive skills development programme, workshops and networking events, research prizes and 24/7 study and social facilities. In addition, the student will participate in selected courses of TWI Ltd’s graduate development programme and will be encouraged to work towards Chartered Engineer status with the relevant Professional Institute (for example, IOP and IOM³).

Eligibility: The studentship provides a tax free stipend of £16,000 per annum for the duration of the studentship plus tuition fees at the UK/EU rate. NOTE: UK students and those EU students who have been resident in the UK for a minimum of three years are eligible for a full award comprising fees and stipend. Other EU students are eligible for a fees-only award. To see if you would be eligible for a full or fees only award, please refer to the EPSRC's residency eligibility criteria: EPSRC Studentship Funding Guide.

Candidates should hold a 2.1 Hons degree in Materials Science, Metallurgy Engineering, Physics or Chemistry, or a 2.2 Hons degree with a relevant postgraduate qualification.

Interested applicants should forward an up to date CV, covering letter and the names and contact details of two referees. Applications should be sent by e-mail marked for the attention of Dr N. Hari Babu, Brunel University, Uxbridge, Middlesex UB8 3PH at mtsthbn@brunel.ac.uk

Informal enquiries about this position are also welcome by email.

Closing date: 31 January 2013 (but early responses are recommended)

PhD Studentship

Solidification Assessment and Modelling of Functionally Graded Materials using Laser Metal Deposition (LMD)

PhD Studentship between TWI Ltd and Brunel University

Location: TWI Ltd (Sheffield, South Yorkshire) and Brunel University (Uxbridge, West London)

Duration: Three years

Bursary: £16,000 p.a. plus fees

Start date: February/March 2013

Project

The Laser Additive Manufacture Section at TWI is focused on developing laser additive manufacture for a wide range of materials and applications. The Section has established a capability in the application of Laser additive manufacture, both for blown powder systems and powder bed systems.

There is significant industrial need to improve the surface wear and corrosion characteristics of components in many industrial sectors, including mining, power generation and transport. One solution is the cladding of composite materials (ceramic particles dispersed in a metal matrix) in functionally graded layers using the Laser Metal Deposition (LMD) process.

The aim of this project is to develop a solidification model and computational tools that will help predict LMD cladding properties containing dispersed ceramic particulates in functional graded layers. The choice of symbiotic materials, solidification and cooling rates and levels of ceramic dispersion will all need consideration in a model to predict cladding adhesion characteristics and material properties. The phenomena of melt pool behaviour and surface tension driven fluid flows on ceramic particle distribution will also be included in the study.

Supervisors

The project will be jointly supervised by Brunel University (www.brunel.ac.uk) and TWI Ltd. (www.twi.co.uk). The university academic supervisors will be Professor Dmitry Eskin and Dr Hari Babu Nadendla in the Brunel Centre for Advanced Solidification Technology (BCAST) and the industrial supervisor will be Dr Carl Hauser at TWI Ltd. The student will be based primarily with the sponsor company, TWI Ltd (located in Sheffield), working with state-of-the-art Laser Metal Deposition and processing equipment, returning to the University to attend events such as scientific and non-scientific short courses, meetings, and to use characterisation facilities. The costs of travel and accommodation associated with the time spent at Brunel University will be covered by TWI Ltd.

Professional Development

Brunel Graduate School supports all postgraduates and early career researchers with the university through the provision of a comprehensive skills development programme, workshops and networking events, research prizes and 24/7 study and social facilities. In addition, the student will participate in selected courses of TWI Ltd’s graduate development programme and will be encouraged to work towards Chartered Engineer status with the relevant Professional Institute (for example, IOP). A suitable mentor will be provided by TWI Ltd.

Eligibility

Applicants should have or expect to obtain the equivalent of a 2.1 or first class undergraduate degree in engineering, materials science or physics and should have excelled in previous study of physics, materials and/or mathematics. A postgraduate degree in these subject areas is desirable, but not a necessity. Applicants should be UK citizens, or EU citizens who have been resident in the UK for the three years preceding the date of application.

Applications should be sent by e-mail marked for the attention of Professor Dmitry Eskin, Brunel University, Uxbridge, Middlesex UB8 3PH Dmitry.Eskin@brunel.ac.uk         

Applications are currently being accepted for this vacancy.