Edge chipping mechanism and failure time prediction on carbide
cemented tool during drilling of CFRP/Ti stack
Received: 13 September 2016 /Accepted: 4 January 2017 /Published online: 13 January 2017
Springer-Verlag London 2017
Abstract To investigate the edge chipping during drilling of
the CFRP/Ti stack with carbide cemented tools, a drilling
experiment was carried out and a tool failure model was pro-
posed. Thrust force, drilling temperature, and tool wear were
analyzed. A tool stressing model and a tool failure model of
edge chipping were constructed respectively. On the basis of
these, the prediction model on the edge chipping was
established to forecast the failure time. Drilling temperature,
Vickers hardness, and cutting speed were considered during
the prediction model building. The results demonstrate that
adhesive wear has a great influence on the edge chipping.
The damage of adhesive wear for tool rake face leads to the
load variation on rake face and the initial crack. Under the
action of shear stress, the crack starts at rake face and then
expands to the flank face, resulting in tool edge chipping. The
affinity interaction (between titanium alloy with carbide
cemented) and the thermal residual stress are two critical fac-
tors for tool edge chipping. Tear easily occurs inside the bind-
ing phase or at the boundary between hard phase and binder
phase. As the drilling temperature increases, the hardness of
the carbide cemented will gradually decrease. The prediction
result of failure time is similar to the experimental result, and
the effectiveness of the prediction model is verified.
Keywords CFRP/Ti stack
Carbon fiber reinforced plastics (CFRPs) and titanium alloy
both have a series of advantages such as light quality, high
specific strength, fatigue resistance, corrosion resistance, etc.
Therefore, using these two materials can greatly increase air-
crafts’ life, reduce structural weight and fuel consumption,
and save the maintenance costs [1–6]. The usage amount of
composite and titanium alloy has already become one factor of
the significant technical index on the aircraft evaluation .
With a wide utilization in the aircraft industry, there are a mass
of requirements on connecting and assembling between the
two parts. Mechanical fastening with bolts and rivets has been
the suitable way to assemble the composite and titanium alloy.
And the assembly accuracy fully relies on the hole quality and
riveting quality. In order to ensure the hole quality and boost
productivity simultaneously, machining in one pass with a
single drill has been the preferred method, instead of drilling
these two parts respectively and then assembling . Besides,
both CFRP and titanium alloy can lead to serious tool wear
during drilling. Therefore, it is an extremely challenging task
to solve the problem about rapid tool wear during drilling the
CFRP/Ti stack .
Carbide cemented is a kind of reliable and common tool
material due to several advantages, such as high strength,
hardness, and fracture toughness. Carbide cemented tools
are widely used in the cutting field such as composite, titani-
um, high temperature alloy, etc. [10, 11].
Quantities of studies have been done on carbide cemented
tools with respect to tool life. Poutord et al.  and Park et al.
 used carbide cemented tools for drilling CFRP/Ti stack.
Their results demonstrated that titanium alloy revealed strong
affinity with tool materials at temperatures above 500 °C.
Titanium alloy reacted to chemical reaction with carbide
cemented, thus forming a built-up edge (BUE) welded to
* Ben Wang
Key Laboratory of Fundamental Science for National Defense of
Aeronautical Digital Manufacturing Process, Shenyang Aerospace
University, Shenyang, Liaoning 110136, China
Int J Adv Manuf Technol (2017) 91:3015–3024