Transparent ceramics to make bullet resistant glass lighter and stronger
Scientists from Tomsk Polytechnic University are developing a transparent ceramics production technology which can be used to make bullet resistant and armor glasses for military and aerospace equipment. TPU technology will reduce the weight of such glasses by two-three times, thus increasing their ballistic strength.
Photo: Aleksey Khasanov demonstrates the process of spark-plasma sintering of ceramics
TPU development will makes it possible to achieve the best characteristics of bullet resistant and armor glass for military vehicles, portholes and protective caps of aviation and space equipment.
‘Transparent ceramics can reduce the weight of bullet resistant glass by two-three times. Now it represents a multi-layer glass. It is quite thick and heavy. Transparent ceramics can replace some layers, since it is much stronger than glass and meets relevant transparency characteristics. As a result, ballistic resistance of such combined glass is improved, it becomes lighter as it consists of fewer layers, while being stronger,’ says Professor Oleg Khasanov, the Head of the Department of Nanomaterials and Nanotechnology, Director of TPU NanoCenter.
He notes that now transparent ceramics is important for many industries: optic engineering, sensors and scintillation technology, laser technology. It can be applied as armor material in combination with layers of bullet resistant glass.
According to scientists, similar technologies are already being applied in foreign countries, while in Russia such combined armor consisting of glass and ceramics is not produced yet. One of the challenges in this area is the lack of domestic industrial production of high-purity nanopowders with required properties. The objective of the research team is to create the first domestic industrial technology for transparent ceramics.
‘It comes both about the development of new methods for sintering of ceramics nanopowders and methods of molding products from it, i.e. the creation of products with necessary shapes and sizes,’ explains Oleg Khasanov.
The main difference between TPU technology and its analogues is the use of dry ceramic nanopowders which do not contain binders and plasticizers.
Due to the absence of impurities, nanoceramic products have better quality. The optimal technological pressing modes, sintering temperature and a number of other factors are also important. Only all this combined makes it possible to obtain products of the required quality.
‘The density of transparent ceramics should make 100%. If there are more pores in the material than 10 per 1 million grains around, ceramics won’t be sufficiently transparent; the size of such pores should not exceed 10 nanometers. There should be no distortion at grain boundaries. Only then light will pass through without absorption and dispersion,’ says Oleg Khasanov.
To say more, at present ceramics is used in different areas: electronics, radio engineering, defense industry, oil and gas, nuclear, aerospace, automotive and many others, as well as in power engineering and medicine. Ceramic materials have a unique set of operational properties: wide temperature range of application (ranging from space cold to plasma temperature in rocket engine nozzles), predetermined strength and electrophysical properties.