Introduction
Abrasive water jet cutting is an extended version of water jet cutting; in which the water jet
contains abrasive particles such as silicon carbide or aluminum oxide in order to increase the
material removal rate above that of water jet machining. Almost any type of material ranging
from hard brittle materials such as ceramics, metals and glass to extremely soft materials such
as foam and rubbers can be cut by abrasive water jet cutting. The narrow cutting stream and
computer controlled movement enables this process to produce parts accurately and
efficiently. This machining process is especially ideal for cutting materials that cannot be cut
by laser or thermal cut. Metallic, non-metallic and advanced composite materials of various
thicknesses can be cut by this process. This process is particularly suitable for heat sensitive
materials that cannot be machined by processes that produce heat while machining.
The schematic of abrasive water jet cutting is shown in Figure 15 which is similar to water
jet cutting apart from some more features underneath the jewel; namely abrasive, guard and
mixing tube. In this process, high velocity water exiting the jewel creates a vacuum which
sucks abrasive from the abrasive line, which mixes with the water in the mixing tube to form
a high velocity beam of abrasives.
Applications
Abrasive water jet cutting is highly used in aerospace, automotive and electronics industries.
In aerospace industries, parts such as titanium bodies for military aircrafts, engine
components (aluminium, titanium, and heat resistant alloys), aluminium body parts and
interior cabin parts are made using abrasive water jet cutting.
In automotive industries, parts like interior trim (head liners, trunk liners, door panels) and
fibre glass body components and bumpers are made by this process. Similarly, in electronics
industries, circuit boards and cable stripping are made by abrasive water jet cutting.
Advantages of abrasive water jet cutting
In most of the cases, no secondary finishing required
a) No cutter induced distortion
b) Low cutting forces on work pieces
c) Limited tooling requirements
d) Little to no cutting burr
e) Typical finish 125-250microns
f) Smaller kerf size reduces material wastages
Special Features
a) No heat affected zone
b) Localizes structural changes
c) No cutter induced metal contamination
d) Eliminates thermal distortion
e) No slag or cutting dross
f) Precise, multi plane cutting of contours, shapes, and bevels of any angle.
Limitations of abrasive water jet cutting
a) Cannot drill flat bottom
b) Cannot cut materials that degrades quickly with moisture
c) Surface finish degrades at higher cut speeds which are frequently
used for rough cut