Abstract.One of the main present industry challenges is finding the most efficient manufacturing process for a certain part. When parts are made of strong steels like Hardox, their fabrication method is usually difficult. Abrasive waterjet cutting (AWJ) is one of the cutting processes which can be used in this case. This paper presents an experimental research on the machinability of Hardox steel by AWJ. The experiments were conducted using a factorial design model considering two of the main influence parameters like the traverse speed and the distance between the nozzle and the surface of the material. Based on the measurement of the dimensions and the roughness of the parts, the influence of the parameters was revealed and analyzed. The manufacturing time was also compared, as it directly influences the production cost. Further research is considered to develop a mathematical model which can be used for a proper choice of the process parameters depending on the initial requirements.

Abstract. The manufacturing process of special steels like Hardox is usually difficult. Abrasive waterjet cutting (AWJ) is one of the machining processes which can be used in this case, with good results, as proved in previous research of the authors. This paper presents an experimental study on the influence of the AWJ main process parameters to the dimensional accuracy of holes manufactured in Hardox steels. The experiments were conducted using a L8(2 4 ) fractional factorial design matrix considering four parameters: the traverse speed, the part thickness, the hole dimension and the material type. Based on the measurement of the dimensions of the holes, the influence of those parameters was revealed and analyzed. The manufacturing time was also registered, as this parameter directly influences the production cost. Further research aims developing a mathematical model which will be a useful tool in workshop process planning.

ncremental sheet forming (ISF) is one the manufacturing methods for sheet metal parts which has an increased rate of flexibility combined with relatively simple and cheap common technological equipment. This paper presents the results of researches on ISF performed on a CNC lathe, for thin sheet parts made of DC04Am mild steel. The main objective of the paper was to establish the maximum wall angle of the parts and its dependence on the main parameters of the process: thickness and diameter of the part, the tool radius, the feed rate, the spindle speed and the lubricating/cooling conditions. The tests were performed with original equipment designed by the authors and the results were commented and presented in diagrams and images of the parts. The main conclusion is that ISF on a CNC lathe can be successfully used for manufacturing conical shaped parts made of mild steel thin sheet, having a certain maximum angle of the parts wall, for small sized batches. The limit values of the parameters analyzed are a useful technological database for engineers.

The manufacturing of aluminum honeycomb panel are usually difficult. The abrasive waterjet method can offer a suitable solution. This paper presents the results of some experiments on waterjet cutting of circular holes into aluminum honeycomb panel, which can be further used for cutting holes in aluminum honeycomb panel . The main problem which occurs is the tapered shape of the hole, due to the mechanics of the process and the control of the kerf produced by the waterjet. The experiments considered several values of the main process parameters like the pump pressure and the feed rate which have a direct influence on the part machineability. After measuring the parts, there were analyzed the main dimensional parameters of precision to reveal the proper solution for obtaining the required quality of the process.

This paper presents an experimental investigation on the abrasive waterjet machining (AWJM) of Hardox steels. A full factorial plan was designed and carried out to determine how the traverse speed, the material thickness, and the material type influence the surface roughness. Two materials were machined during the experiments: Hardox 450 and Hardox 500. The experimental data were analysed using statistical methods, and a mathematical model was obtained. Additional experiments were made to validate the model. The results proved that the analysis is accurate and the mathematical model will be a useful tool in industrial environments for process planning when abrasive waterjet machining is used for the considered material.

Incremental forming is one of the manufacturing methods which uses relative simple technological equipment and can assure a high rate of the process flexibility. These requirements can assure the efficiency demanded by the industrial market, in the case of small production batches, which occur more and more often nowadays. To ensure the stability of the process, the required quality and dimensional accuracy of the parts have to be well controlled. This requires the evaluation of the parts dimensions by certain measurements. For hollow parts, the measurement of their thickness is always a challenge, mainly when the dimensions are smaller and their depth is greater. This paper presents a digital method for the parts dimensional evaluation and analysis, which can be very accurate and does not need mechanical contacts with the part during measurements. The parts were scanned with a 3D blue light scanner, on their both sides and then the data was processed into specialized software, to obtain the parts digital surface from the 3D scanned data. The digital data was compared with the theoretical approach, to establish some conclusions on the validity of the sinus law and to point out the critical zones, where the thinning is strong and may cause fractures. The digital scanning method presented can be used also for quality control and inspection, as the processing steps are considered user-friendly and easy to adapt to certain specific requirements.

The progressive screw shaft is one of the very challenging part for machining. It might have a decisive influence on the precision of the parts processed by the machine tool. In this paper is presented a new, innovative technology of its manufacturing. The first goal is to develop a technological process for CNC milling machine. Technological process is fully described and with all parameters given and commented. Technology for progressive screw shaft manufacturing is developed in Autodesk Inventor HSM software. The second goal of the paper is a comparative analysis of the here described process for milling the different profile shapes. In the paper are given the milling examples of rectangular and circular profiles. Paper aims to emphasize the advantages and disadvantages of the proposed method. Some conclusions and directions to next research steps are given at the end of the paper.

The electrical steel laminations which compose the rotor and stator core for electrical motors have complex 2D shapes. When these parts require small batches of production, they can be efficiently manufactured only by flexible methods. The paper presents the results of using abrasive waterjet machining (AWJ) to obtain such parts within the frame of a research project with EU funding. The main objective of the research was the analysis of geometrical and dimensional accuracy of the parts which will confirm that AWJ is a suitable process in this case. The parts were measured on an optical digital profilometer. The measurement process was not simple because the parts are relatively large and cannot be focused only by one shot by the camera. Also, another important issue were the profile edges inconsistencies due to the burrs. Those problems and the limitations of the measurement technology did not allow the automation of measurement. The results and discussions proved that AWJ can be used successfully for manufacturing such parts and the machining process is traceable.