Analytical modeling of kerf profile for 3-axis abrasive waterjet machining (AWJM)

Official URL: http://risc01.sabanciuniv.edu/record=b1917991 (Table of Contents)

Abrasive water jet machining (AWJM) processes can be used to machine materials difficult-to-cut materials, i.e. very soft or very hard, from foams, composites to nickel and titanium alloys, which are difficult to cut with conventional milling methods due to material softness issues or very low tool life. However, it is currently being used in the production of profile geometries for the purpose of 2-axis circumferential (routing) cutting where the part is cut thoroughly in industrial applications. The erosion rate in AWJM processes, and hence the cutting depth value, depends on several parameters such as pump pressure, amount of abrasive, jet angle and traverse speed (feed) of jet. If the cutting depth to which the water jet acts on the surface can be known in relation to the process parameters, more efficient process conditions can be found, and it can be used as even 5-axis machining process rather than just 2-axis. In this thesis, the theoretical modelling of 3-axis abrasive water jet processes is studied. The theoretical analysis is verified by experimental analysis and discussions are provided. Although AWJM processes provide significant advantages in machining of difficult-to-cut, the knowledge in this area is limited. As being a relatively new process, process modelling, application and parameter selection issues require further investigations. In this thesis, modelling of the abrasion space ("kerf") of 3-axis AWJM processes, the effect of abrasive process parameters on the process performance and the estimation of iii the machined part surface were studied. In addition, compensation techniques for dimensional errors caused by the process is discussed to be applied on 5-axis toolpaths. The developed model is experimentally verified and, if necessary, corrections performed on the process model. The thesis also includes the application of the 3-axis AWJM process to the industry and analyze the economic and usefulness of this manufacturing process. Parts from different sectors which may be potentially advantageous for AWJM are selected and efficient processing conditions are determined using process models developed in the thesis. The field of development of the thesis is an important contribution to the necessary knowledge and scientific infrastructure both in academic and industrial aspects.