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.
Joint strength of aluminum ultrasonic soldered under liquidus temperature of Sn–Zn hypereutectic solder
Abstract In order to obtain high-strength aluminum joints, ultrasonic soldering of 1070 aluminum was conducted under liquidus temperature of Sn–Zn hypereutectic solder. A device for ultrasonic soldering was assembled, which propagated ultrasonic vibrations in a direction perpendicular to joining surfaces. This device joined 1070-Al using quasi-melting Sn–Zn hypereutectic solder without using any artificial spacers. The strength of the solder joints was evaluated by tensile tests. The optimum joining conditions were determined, and the effects of solder compositions and soldering temperature on the joint strength and the solder layer thickness were examined. In this ultrasonic soldering process, the highest tensile strength was obtained for the solder joints fabricated at 220 °C for the Sn–23Zn and Sn–40Zn solder compositions. The joint strength was equivalent to that of 1070-Al heat treated at 220 °C. The sound joints were obtained at 300 °C using Sn–82Zn solder, the liquid phase volume fraction of which was theoretically only 0.24. The present work also revealed that the thickness of retained solder layer in the joint after ultrasonic soldering could be estimated. Accordingly, ultrasonic soldering under the liquidus temperature of Sn–Zn hypereutectic solder could be a spacer-free soldering method to obtain high-strength aluminum joints.