The aim of this investigation is to study the performance of the new generation of the PVD coated grade and to map the influence of cutting conditions on the tool life in milling of ADI
The aim of this investigation is to study the performance of the new generation of the PVD coated grade and to map the influence of cutting conditions on the tool life in milling of ADI (Austempered Ductile Iron). The results show that chipping is the main wear mechanism which determines the tool life in dry condition and notch wear in wet condition for this application. This due to the different stress mechanisms and preexisting cracks in the coating. The wear development shows clearly that the new PVD coating (C20) has the best ability to delay the chipping growth. It was also found that a high content of Al in the new coating (C20) was especially favorable compared to a TiAlN multilayer with lower Al content (C30) or CVD coating. This is due to fine grains and low compressive stress level in the coating which increase the coating ability to withstand the mechanical and thermal impact. It was also found that the use of coolant decreases the tool life with 70-80% compare to dry milling. Keywords—Austempered Ductile Iron (ADI), coating, chipping, milling, tool performance.
Successfully Machining Austempered Ductile Iron (ADI)
Austempered Ductile Iron (ADI) is a relatively new material to the industrial marketplace. Many have tried to machine ADI as if it were steel, or as-cast Ductile Iron, and have been unsuccessful. Because of this, a myth has developed that ADI is not machinable. When the material properties and metal matrix of ADI are taken into consideration, ADI can be successfully machined.
Investigation on reduction of cement binder in cold bonded pelletization of iron ore fines
Abstract Cold bonded pelletization processes developed for utilization of iron ore fines and slimes require about 10% or more cementitious binders. Reduction of the cost of the pellet and its gangue content require reduction of the amount of binder. This communication reports the results of an investigation on reduction of binder requirement in cold bonded pelletization of iron ore fines by using cement clinker alone or mixed with silica of different characteristics. Pellets with crushing strength of 100–200 kg/pellet could be obtained even using about 4–6% binders consisting of Portland cement clinker/cement of appropriate chemical characteristics and fineness either alone or mixed with silica fines. The binder requirement may be curtailed by about 4% by increasing its surface area. The physico-metallurgical properties of the cured pellets indicate potentiality for use as burden material in low/moderate shaft furnaces.