Lm-37
Module
9 Non conventional Machining
Version 2 ME, IIT Kharagpur
Lesson
37 Water Jet and Abrasive Water Jet Machining
Version 2 ME, IIT Kharagpur
Instructional Objectives o o o o o o o o o o o o o List four different non conventional machining processes Differentiate between water and abrasive water jet machining List different WJM and AWJM systems List ten different modules of AWJM systems List four applications of AWJM List three advantages of AWJM List materials that can be processed by AWJM Mention functions of different elements of AWJM Identify mechanism of material removal Develop models for mechanism of material removal Identify parameters related to product quality Identify five limitations of AWJM Identify environmental issues in the area of AWJM
Introduction
Water Jet Machining (WJM) and Abrasive Water Jet Machining (AWJM) are two non-traditional or non-conventional machining processes. They belong to mechanical group of non-conventional processes like Ultrasonic Machining (USM) and Abrasive Jet Machining (AJM). In these processes (WJM and AJWM), the mechanical energy of water and abrasive phases are used to achieve material removal or machining. The general grouping of some of the typical non-traditional processes are shown below: o Mechanical Processes ⎯ USM ⎯ AJM ⎯ WJM and AWJM o Thermal Processes ⎯ EBM ⎯ LBM ⎯ PAM ⎯ EDM and WEDM o Electrical Processes ⎯ ECM ⎯ EDG ⎯ EJD o Chemical Processes ⎯ Chemical milling ⎯ Photo chemical machining WJM and AWJM can be achieved using different approaches and methodologies as enumerated below: • WJM - Pure • WJM - with stabilizer • AWJM – entrained – three phase – abrasive, water and air • AWJM – suspended – two phase – abrasive and water
Version 2 ME, IIT Kharagpur
o Direct pumping o Indirect pumping o Bypass pumping However in all variants of the processes, the basic methodology remains the same. Water is pumped at a sufficiently high pressure, 200-400 MPa (20004000 bar) using intensifier
9 Non conventional Machining
Version 2 ME, IIT Kharagpur
Lesson
37 Water Jet and Abrasive Water Jet Machining
Version 2 ME, IIT Kharagpur
Instructional Objectives o o o o o o o o o o o o o List four different non conventional machining processes Differentiate between water and abrasive water jet machining List different WJM and AWJM systems List ten different modules of AWJM systems List four applications of AWJM List three advantages of AWJM List materials that can be processed by AWJM Mention functions of different elements of AWJM Identify mechanism of material removal Develop models for mechanism of material removal Identify parameters related to product quality Identify five limitations of AWJM Identify environmental issues in the area of AWJM
Introduction
Water Jet Machining (WJM) and Abrasive Water Jet Machining (AWJM) are two non-traditional or non-conventional machining processes. They belong to mechanical group of non-conventional processes like Ultrasonic Machining (USM) and Abrasive Jet Machining (AJM). In these processes (WJM and AJWM), the mechanical energy of water and abrasive phases are used to achieve material removal or machining. The general grouping of some of the typical non-traditional processes are shown below: o Mechanical Processes ⎯ USM ⎯ AJM ⎯ WJM and AWJM o Thermal Processes ⎯ EBM ⎯ LBM ⎯ PAM ⎯ EDM and WEDM o Electrical Processes ⎯ ECM ⎯ EDG ⎯ EJD o Chemical Processes ⎯ Chemical milling ⎯ Photo chemical machining WJM and AWJM can be achieved using different approaches and methodologies as enumerated below: • WJM - Pure • WJM - with stabilizer • AWJM – entrained – three phase – abrasive, water and air • AWJM – suspended – two phase – abrasive and water
Version 2 ME, IIT Kharagpur
o Direct pumping o Indirect pumping o Bypass pumping However in all variants of the processes, the basic methodology remains the same. Water is pumped at a sufficiently high pressure, 200-400 MPa (20004000 bar) using intensifier
References: [1] P. J. Engels, Impact wear of materials, Chapter 4 by Finnie, Elsevier, 1978 J. G. A. Bitter, A study of erosion phenomena Part I, Wear, Vol.6, 1953, pp.5-21 J. G. A. Bitter, A study of erosion phenomena Part II, Wear, Vol.6, 1953, pp.5169-190 M. Hashish, A model for abrasive water jet machining, J. Engg. Materials Tech., Vol.111, (1989), pp.154-162 J. Zeng and T. J. Kim, An erosion model of polycrystalline ceramic in abrasive water jet cutting, Wear, Vol.199(2), (1996), pp.275-282 [2] [3] [4] [5] Version 2 ME, IIT Kharagpur