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BRAZE JOINING SYSTEMS FOR STEEL SILICON NITRIDE AUTOMOTIVE COMPONENTS

Objective

The overall objective of this project is to develop an integrated metal to ceramic brazing technology, based on 'active' brazing and suitable for mass production, which enables the design of the joint and the choice of joint materials to be optimised for a wide range of applications. The specific objective is to select, manufacture and optimise multilayer brazing structures to join a steel automotive engine component to a silicon nitride based ceramic. A mechanical tappet has been selected as the component which will be used to demonstrate this technology.
The overall aim of this research is to develop an integrated metal to ceramic brazing technology, based on active brazing and suitable for mass production, which enables the design of the joint and the choice of joint materials to be optimised for a wide range of applications. The specific aim is to select, manufacture and optimise multilayer brazing structures to join a steel automotive engine component to a silicon nitride based ceramic. A mechanical tappet has been selected as the component which will be used to demonstrate this technology.

A finite element model was developed to predict the stress and deformations in multilayer brazed structures. It was used to finalise the joint design for the production of trial tappets.
Active brazing alloy tapes, manufactured by rapid solidification to produce enhanced metallurgical characteristics over conventional processing, were successful in vacuum brazing trials.
Using the above as a basis, sample tappets were manufactured for service trials. Laboratory assessment is presently underway and if successful will be followed by full scale engine testing.
THE COMPONENT SELECTED FOR THIS PROJECT IS AN AUTOMOTIVE ROCKER ARM AND THE EXPECTED BENEFITS WILL DERIVE FROM A REDUCTION IN COST, WEIGHT AND IN THE WEAR OF ENGINE COMPONENTS.
THE PROJECT INVOLVES A NUMBER OF INNOVATIVE STEPS IN THE DEVELOPMENT OF METAL/CERAMIC JOINING TECHNOLOGY, THESE INCLUDE:

- ESTABLISHING, FOR THE FIRST TIME, A RELIABLE DESIGN METHODOLOGY RELATING TO MATERIAL CHARACTERISTICS.

- THE APPLICATION OF ADVANCED SPUTTERING TECHNIQUES TO PROVIDE MULTI-LAYER BRAZE STRUCTURES FOR EVALUATION OF EXPERIMENTAL MATERIALS SYSTEMS.

- THE APPLICATION OF ADVANCED MANUFACTURING TECHNIQUES TO PRODUCE MULTI-LAYER BRAZE MATERIAL BASED ON, FOR EXAMPLE, RAPID SOLIDIFICATION AND ROLL-BONDING PROCESS.

SUCCES IN THE PROJECT WOULD REPRESENT A MAJOR TECHNOLOGICAL ADVANCE IN THE DEVELOPMENT OF METAL/CERAMIC JOINING TECHNOLOGY.

IN THE AUTOMOTIVE FIELD, IF THE OUTCOME PERMITTED A 10% WEIGHT REDUCTION IN THE CAM-FOLLOWER SYSTEM, THIS COULD ULTIMATELY RESULT IN A SAVING IN FUEL CONSUMPTION IN THE EEC OF AS MUCH AS 50 MILLION ECU PER ANNUM.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

JOHNSON MATTHEY PLC (TRADING AS SYNETIX)
Address
Blounts Court, Sonning Common
RG4 9NH Reading
United Kingdom

Participants (2)

PEUGEOT SA
France
Address

Velizy-villacoublay
THE WELDING INSTITUTE
United Kingdom
Address
Granta Park, Great Abington
CB1 6AL Cambridge