17/18 January 2007 Wiener Neustadt - Czelo

market economy. The Technical University of Sofia warmly welcomes the youth of Bulgaria aspiring to devote
their lives and work to contemporary technology.
1. Profile: RTD: Nanostructured Matrix in Austempered Ductile Irons and Steels
DESCRIPTION:TECHNOLOGY OFFER
TECHNICAL DESCRIPTION
OFFER
•Background:
Austempered Ductile Irons (ADI) have been very promising materials for many kinds of applications. Quality of
castings and permanent control of austempering process are the key factor in manufacturing of ADI-products.
The quality of castings subjected to austempering is well established by American and European specialists. But
important problems are still opened in austempering technology. The safety reason and the production costs
have become more important in high series productions. That is why we start to study the thermal cycle
parameters of austempering treatment by experimental simulating in order to get variable microstructures
including matrix nanostructure and test mechanichal properties. After ten years research we have enormous data
about ADI and start to integrate mathematical modelling and experimental simulating. The aim is to predict
structure-properties relationships for ADI materials and components behaviour in practice.
Description of product / process:
Austempered Ductile Irons have recently been developed as a new engineering materials. ADI are grades of
irons with stabilised austenite matrix with embedded bainitic ferrite needles and graphite nodules. The ADI could
be considered as natural composite materials with excellent yield strength / elongation combinations, excellent
fatigue strength, good machining properties, reduced noise, low production cost. The matrix microstructure of ADI
is responsible for excellent combinations of mechanical properties. Nano-scale microstructure of ADI matrix is a
challenge for scientists and engineers.
What does the product or process do?
ADI offer excellent combinations of mechanical properties as high strength and ductility, very good impact
strength and fatigue, better wear resistant at lower hardness due to graphite presence. ADI replace steel
castings, weldments and forgings, aluminium components. The growth of ADI is as much an economic as a
technical event & converting a medium volume steel component to ADI is approximately 20%. The savings rises
to 30% when replacing Aluminium with ADI. The high strength-to-weight ratio makes ADI material attractive
alternative.
How does the product or process work?
ADI are produced by subjecting of ductile irons to an austempering treatmen austenitization in the range of 850-
950°C for 60-120 min., fast cooling to avoid pearlite tramsformation up to austempering temperature region 250-
420°C for austenite- bainite transformation and air cooling to room temperature.
Under what conditions does the product or process work?
The austempering treatment is carried out in salt baths. The environmentally-friendly production of Austempered
components is available in a modern, atmosphere-to-salt heat treating system ( USA-Wisconcin)
What are the applications of the product or process?
At Europe- UK-West Bomwich-The largest austempering furnace in Europe. Austempering work comes from
mainland Europe as well as the UK; demand is growing at around 30% year on year. Research in ADI-The
University of Cambridge-camshafts and modelling the mechanical properties of ADI.
Nort America for 5 million tons by 2005 : 26%- Heavy vehicle; 25% - Light Vehicle; 16% Railroad Equipment;
14%-Agriculture; 11%-General Manufacture; 8% -Constr./Mining
ADI applications continue to emerge: metal-on-metal railroad suspension parts, digger teets, crusher and grinder
applications; fertilizer knives; In army-pump components, rollers, heavy duty suspension arms, truck suspension
components; In automotive industry-Tow hooks for light trucks; ADI upper control arms in the Ford Mustang
Cobra; ADI Hypoid Ring Gear and Pinion set; ADI disel engine Timing Gears; ADI Tractor Axle Gear Carrier
HUB; In agriculture- brake backing plates, tractor suspension components and power transmission components.
Agricultural application of CADI are starting to grow rapidly- CADI Plow PoAnouder intriguing application for ADI
are very large in sectioncastings-one meter in diameterint. Carbidic Austempered Irons (CADI) are ductile irons
containing carbides that are subsequently austempered to produce an ausferritic matrix with an engineered
amount of carbides.