Roadmap to Membership of RICS - Pathways and Routes
Bulletproof vest with ceramic insert
1. Bulletproof Vest with Ceramic Insert
DEPARTMENT OF MECHANICAL & MANUFACTURING ENGINEERING
FACULTY OF ENGINEERING & BUILT ENVIRONMENT
UNIVERSITI KEBANGSAAN MALAYSIA
FAISAL HUSAINI BIN BADRI
MOHAMAD FAIZ BIN MOHAMAD ZAIS
MUHAMAD NAJIB BIN ROSLAN
2. Acknowledgement
Special thanks to our lecturers PROF. DR. ANDANASTUTI MUCHTAR
and DR. NABILAH AFIQAH MOHD RADZUAN for teaching and
guiding us in KKKM4672 Processing of Ceramics course.
3. What is Bulletproof Vest?
Bulletproof vest or body armour is defensive gear to withstand or
avoid them for physical attacks. This is traditionally used in the
protection of military personnel and is generally often used in various
forms of police (in particular the riot police); private security guards
or bodyguards; and, at times, ordinary civilians.
Currently , there are two primary styles: standard body armor for
moderate to substantial defense and hard-plate reinforced body
armor for maximum protection, as used by military combatants.
4. Material
Ceramic armours are designed to absorb blast debris and to avoid
the penetration of bullets.
Alumina, Boron Carbide, Silicon Carbide,and Titanium Diboride are
ceramic that commonly being used in armour.
Ceramic armour never used as naked ceramic tiles, but must be
wrapped in fibre-reinforced polymer (FRP) cladding.
It is important that the ceramic is fragile enough for the projectile to
pulverize.
Ideally the ceramic density should be as low as possible for minimum
Areal Density and maximum Equivalent Mass performance.
5. Alumina
Alumina (aluminum oxide, Al2O3) is the budget ceramic armour choice.
Usually used in the civilian sector of the ceramic armour industry.
Alumina mosaics is cheaper than others. For example, alumina cost $200 per square
meter and carbides cost more than $1000 per square meter.
Does not required any specialized furnace technology for sintering as it is sintered in
ambient air.
Slow crack propagation velocity (3 km/s) than the shock wave propagation velocity
(10 km/s) which means that brittle fracture is unable to keep pace with the shock
wave.
Mechanical Properties of Alumina:
i. High hardness of alumina 1800 HV
ii. Density of 3.9 g/cm3
iii. Young Modulus of 380 GPa
iv. Flexural Strength > 300 MPa
v. Sintering temperature in range of 1500-1700 °C
6. Manufacturing Process
Manufactured using a combination of two process called Viscous Plastic
Processing (VPP) and Extrusion
VPP is a shaping process which alumina powder is mixed with polyvinyl alcohol
(PVA) as a binder for aqueous system and polyvinyl butyral (PVB) as a binder for
organic solvent system.
They are mixed using a double blade mixer in order to obtain a high shear mix
condition to form a dough.
The high shear mixing breaks down the agglomeration of powder while mixing.
As the dough is obtained, it is processed into more complex shapes through
extrusion process which act as the secondary forming method.
Extrusion is a process involving compaction and shaping of a highly viscous by
forcing it through a nozzle.
Extruded compacts will undergo drying process and sintering process.
The liquid solvent is removed by evaporation during drying process and the
binder will be eliminated during sintering process at temperature range of 300°C–
700°C.
8. Local Manufacturer
Most local company import the bullet proof vest from the
international market player.
However, Stec Advance Equip emerged as one of small growing
company which manufactured bullet proof vest and body armour
in Malaysia.
Stec Advance Equip are an OEM manufacturer and had a
manufacturing plant composed of 100 staff entirely concentrated
on making world-class security vest for the armed forces and private
protection service.
Their main target market is USA and local military.
9. Technology And Improvisation
Over the years, researchers are more interested towards the study of ceramics insert
rather than the backing material.
This is because armour which made mainly from metal reduced the impact by plastic
deformation while armour which mainly consists of ceramics tend to reduce the
impact by efficient energy absorption and excellent load-spreading mechanism.
Ceramics remain as the most important material which influenced the military world
due to their effectiveness against heavy ammunition.
Injection molding has emerged as one of the most important in polymer processing
nowadays. However, this process is not well known and preferable in the
manufacturing of ceramics insert.
This is because of their success criteria mainly depend on the selection of binder
system.
The addition of binder in large quantity also will affecting the strength of the product
formed as the binder will leave the body.
Thus, we need to study more on this processing method as this method is very suitable
for producing complex part in a huge scale.
10. References
Appleby-Thomas, G. J., Jaansalu, K., Hameed, A., Painter, J., Shackel, J. & Rowley, J.
2020. A comparison of the ballistic behaviour of conventionally sintered and
additively manufactured alumina. Defence Technology 16(2): 275–282.
Crouch, I. G. 2019. Body armour – New materials, new systems. Defence Technology
15(3): 241–253.
Piconi, C. 2011. Alumina. Comprehensive Biomaterials 1: 73–94.
Ruys, A. 2019. Alumina in lightweight body armor. Alumina Ceramics.
Yang, M. & Qiao, P. 2010. 4 - High energy absorbing materials for blast resistant design. Dlm.
Uddin (pnyt.). Woodhead Publishing Series in Civil and Structural Engineering, hlm. 88–119.
Woodhead Publishing.
Quéfélec, B. & Dartois, M. 2016. 13 - Ceramic-faced molded armor. Dlm. Bhatnagar (pnyt.).
Woodhead Publishing Series in Composites Science and Engineering, hlm. 369–391.
Woodhead Publishing.
Bracamonte, L., Loutfy, R., Yilmazcoban, I. K. & Rajan, S. D. 2016. Design, manufacture, and
analysis of ceramic-composite armor. Lightweight Ballistic Composites: Military and Law-
Enforcement Applications: Second Edition 349–367.
Leo, S., Tallon, C., Stone, N. & Franks, G. V. 2014. Near-Net-Shaping Methods for Ceramic
Elements of (Body) Armor Systems. Journal of the American Ceramic Society 97(10): 3013–
3033.
Cegła, M., Habaj, W. & Podgórzak, P. 2014. Cegła+i+inni.pdf 3(17): 23–34.