Desirability Function Analysis (DFA) in Multiple Responses Optimization of Abrasive Water Jet Cutting Process

This paper introduces optimization of machining parameters for high-pressure abrasive water jet cutting of Hardox 500 steel utilizing desirability function analysis (DFA). The tests were carried out according to the orthogonal matrix (Taguchi) L9. The control parameters of the process such as pressure, abrasive flow rate, and traverse speed was optimized under multi-response conditions namely cutting depth and surface roughness. The optimal set of control parameters was established on the basis of the composite desirability value obtained from desirability function analysis and the significance of these parameters was determined by analysis of variance (ANOVA). The effects show that optimal sets for high cutting depth and small surface roughness is high pressure, middle abrasive flow rate, and small traverse speed. A confirmation test was also leaded to validate the test results. Results of the research have shown that machining efficiency at keeping good level quality of cut surface can be improved this approach.

Analyses of Vibration Signals Generated in W. Nr. 1.0038 Steel during Abrasive Water Jet Cutting Aimed to Process Control

The presented research was aimed at finding a suitable tool and procedure for monitoring undercuts or other problems such as cutting without abrasive or inappropriate parameters of the jet during the abrasive water jet (AWJ) cutting of hard-machined materials. Plates of structural steel RSt 37-2 of different thickness were cut through by AWJ with such traverse speeds that cuts of various qualities were obtained. Vibrations of the workpiece were monitored by three accelerometers mounted on the workpiece by a special block that was designed for this purpose. After detecting and recording vibration signals through the National Instruments (NI) program Signal Express, we processed this data by means of the LabVIEW Sound and Vibration Toolkit. Statistical evaluation of data was performed, and RMS was identified as the parameter most suitable for online vibration monitoring. We focus on the analysis of the relationship between the RMS and traverse speed.

Assessment of the Technological Quality of X5CRNI18-10 Steel Parts after Laser and Abrasive Water Jet Cutting Using Synthetic Index of Technological Quality

Despite extensive knowledge of the cutting methods described, no universal method has been developed so far for evaluating the technological quality of elements shaped by different cutting processes. The aim of the research described in this article was to fill this gap and to propose the author’s methodology for the assessment of the technological quality of the surface of X5CRNI18-10 steel shaped as a result of laser cutting and abrasive water jet cutting. A synthetic index of technological quality assessment of the surface after cutting CTQ (cutting technological quality) was proposed. Three groups of factors were taken into account in the assessment of technological quality of the surface after cutting: selected surface texture parameters (arithmetic mean deviation of the surface Sa and total height of the surface St), results of measurements of dimensional accuracy of cut elements (length deviation LD and width deviation WD) as well as indicators of surface morphology estimated on the basis of microscopic images of the surface after cutting (deformation intensity DI and identification of cutting zones ICZ). On the basis of CTQ values determined, the cutting results of both cutting methods were compared. The analyses presented in this paper proved that the CTQ index can be effectively used to compare the results of a cutting process conducted using different methods and under different conditions. The developed CTQ index is a universal valuation tool, allowing for quantitative evaluation of features related to the technological quality of cutting process results.

Influence of Abrasive Water Jet (AWJ) on Surface Roughness

Abrasive water jet (AWJ) is one of the most advanced and valuable non-traditional machining processes because of its massive advantages of removing metals ranging from hard to soft. This paper focused on studying the influence of jet pressure, feed rate and standoff distance on surface roughness during cutting carbon steel using abrasive water jet cutting. A surface roughness device assessed the surface roughness by performing sixteen experiments to identify the distinct texture of the surface. Based on the experiences, the best surface roughness value was 3.14 μm at jet pressure 300 MPa, standoff distance 4mm and feed rate 30 mm/min. The Taguchi method was introduced to implement the experiments and indicate the most influential process parameters on average surface roughness. The experimental results reveal that feed rate has a significant effect on average surface roughness.

ISIM Own Contributions on Non-Conventional Abrasive Waterjet Cutting Technologies

Modern materials cutting operations are traditionally part of the research priorities and also in the production activities of ISIM Timișoara. In the last decade, within the institute, a special emphasis was placed on the development of the abrasive water jet cutting process as well as on implementing the research results obtained into industrial activities. The paper presents own achievements and contributions of ISIM to the development of the abrasive water jet cutting process in the following directions: cutting technologies for materials with different characteristics, innovative new patentable solutions regarding the cutting process respectively important modules in the composition of the water jet cutting equipment, ways to recycle used abrasive waste, solutions to streamline the process. The proposed solutions have been verified with good results in industrial applications, or have been proposed for analysis and development together with specialists in the field from important research units.