Papers by Keyword: Sawing

Abstract: Sawing with bandsaws is a fast and efficient process for cutting semi-finished parts out of bar stock in the metalworking industry. However, the produced surface quality on the workpiece is low due to the unguided length of the saw blade during the engagement in the workpiece. The kinematic correlation between the thin, unstable structure of the saw blade, only pre-stressed in the cutting direction, and the distance of the two saw blade guides according to the workpiece dimensions leads to an indefinite behaviour of the saw blade in the kerf. Apart from the surface quality, this cutting behaviour also causes a great wear of the tool. With increasing wear of the tool, the process becomes more and more unstable and the cutting loss increases. For an optimization of the sawing process, the influences on the stability of the process are investigated by experiment on a test bandsaw equipped with extensive measurement equipment. This paper examines how the saw blade tension influences the stability of sawing processes subject to tool wear. For this purpose, the saw blade tension is varied in a wide range and the stability of the process is assessed. The results obtained show a great influence of the saw blade tension on the sawing process and form the basis for developing a stand-alone stability control system to automatically adjust the sawing parameters.

Abstract: Fixed-abrasive wires, such as electroplated diamond wires and resinoid diamond wires, employed for slicing ingots have the problems of high tool wear. A novel brazed diamond wire has been developed to overcome these problems. This paper investigates the effect of process parameters, including brazing temperature, brazing time and brazing filler composition, on the brazed diamond wire manufacturing with CuSnTi brazing filler. The 3D micro-video system was used to observe the brazed diamond wire surface. Tensile, bending and torsional test were carried out to evaluate the mechanical properties of brazed diamond wire. A brazed diamond wire with 3km length was fabricated with the optimization process parameters, which was successfully used to slice glass.

Abstract: A temperature model was advanced based on a parabolic heat flux distribution in sawing contact zone in the present paper. It is found that the maximum temperature for parabolic distribution is more higher than that for triangular distribution in the sawing contact zone, and the location point of the maximum temperature for parabolic distribution in the sawing contact zone is much nearer the entrance than that for triangular distribution.

Abstract: t is challenging to achieve good surface quality and high efficiency simultaneously when machining thin film solar panels. In this study the machining characteristics of a multilayered thin film structure were investigated using diamond wire sawing and grinding. It was found that the efficiency in sawing was significantly greater than that of the employed grinding process, but the machined surface quality was much worse. The results indicated that grinding could still be the solution for such processing and sawing must be improved before this technology could be further progressed for machining thin film multilayered structures.

Abstract: Aiming at the problem of poor machinability in conventional drilling of aramid/epoxy composites, the formation reason for fuzzing damage was analyzed. In order to obtain better machining quality, a combined machining technology based on sawing and grinding mechanism was proposed and the corresponding drilling tools were developed. Drilling experiments were conducted to explain the machining performance of the drilling tools. The results show that the sawing drilling tool with negative rake angle can effectively restrain fuzzing damage and the sawing-grinding drilling tool decreases the thrust force about 20%~55% with electroplated diamond abrasives. The combined machining technology of sawing and grinding achieves damage-free machining quality in drilling of aramid/epoxy composites.

Abstract: In the present study, sawing forces of Al2O3 ceramic and wear of metal-bonded diamond cut-off wheel were examined by counting the statistical data of diamond wear and analyzing the force signals under different sawing conditions. The experimental results demonstrated that normal grinding force reduced with the increasing of sawing speed, and rose with the increasing of workpiece feed rate and grinding depth. In all of the variables, sawing depth made the greatest effects on normal grinding froce. The percentage of whole crystal or pull-out crystal decreased and fractured crystal increased as the sawing depth increased or the sawing speed decreased. Among machining factors, sawing speed was the greatest effectors on the wear of diamond cut-off wheel.

Abstract: In order to solve the problem which causes high failure rate and low production efficient in the relay-contactor control system of hydraulic metal band-sawing machine, according to the technological requirement in the sawing process, the article uses PLC as controller to control hydraulic equipment automatically. The results showed that: the control circuit not only satisfies the technological requirement, but also makes sawing more stable and high efficiency.

Abstract: The effects of the machining parameters on the relative position of the resultant force were analyzed in circular sawing of granite with a diamond segmented blade. The horizontal and vertical force components and the power were measured. Calculated tangential and normal force components were subsequently used to calculate the relative position of resultant force besides the horizontal and vertical force components. It was found that the value of the relative position of resultant force in down sawing is less than that in up sawing. The shift of sawing swarf has heavy influence on the relative position of resultant force.

Abstract: The effects of the geometric parameters of a sawblade on the sawing fluctuated temperatures were analyzed based on a fluctuated temperature model advanced in my recent paper. The results show that the sawing temperatures are fluctuated only near the workpiece surface in the sawing zone, the blade segment ratio, the number of segments and the contact angle have great influence on the sawing temperatures, which has the guiding significance for optimal design of the sawblade structure.

Abstract: Continuous homogenizing for extrusion billets has become the accepted standard and state of the art technology. Hertwich Engineering (HE) has, to date, built more than 120 such plants worldwide, which are processing some two thirds of the worldwide extrusion billet production. Batch type homogenizing is still the best suited technology for various alloys which require long holding times, e.g. 4 – 12 hours, as well as for large-only log diameter production. Again, HE has in recent years supplied several batch homogenizing plants. Topics: • Process technology, heating, holding, different types of coolers • New log support saddle design, exit car, no rolling of logs with focus to good billet surface finish • Automated sawing, packing • High efficiency batch furnace and cooler with reversing air and precise temperature regime