Page 15 - Jan-Feb 2018
P. 15

Technology
                                                                                      FocusVVSDSDuu¨¨yykkWtWthh QQ¨¨ddll

   The forging stocks shall be utilised     semi-products for such applications       solution treatment furnaces, aging
to produce selected forged components       are considerably greater than those       ovens together with state-of-the-
in T7452 temper for indigenously            required for missiles, armaments and      art handling, inspection and testing
built combat aircraft applications. The     armour applications.                      facilities for the production of
20 mm and 30 mm thick plates are                                                      aluminium alloys for all varieties of
being utilised for ballistic tests against     Further, following the recent          defence applications.
7.62 mm AP(I) ammunition for                closure of the heat treatment
vehicle armour applications.                facilities for sheets and plates of the      Also, the current practice is
                                            age hardening aluminium alloys            that many of the components are
   Table 1 summarises the details of        at BALCO, Korba, there exists             machined from thick plates and/or
the past and ongoing indigenisation         currently no such facility in any of the  forgings, leading to huge wastage of
activities of aluminium alloys with         aluminium industries in the country.      materials. This necessitates the use
DMRL as the nodal agency. Table 2           The processing of the maximum             of closed die forging of appropriate
further describes the details of the        thickness of the plates at BALCO was,     capacity (35,000 T) to produce near
heat treatment conditions (/tempers)        however, limited to about forty (40)      net shape products.
to which the indigenised aluminium          mm because of the limitations of the
alloys were subjected to.                   capacity of the plate stretcher.             A committee on aluminium
                                                                                      materials, with members from
   Although, DMRL had success                  On the other hand, plates having       ISRO and DRDO, under a national
with the production of aluminium            the maximum thickness of about one        material policy initiative, is currently
alloys for a variety of critical defence    hundred eighty (180) mm are required      looking into the aforementioned
applications, as discussed, the             for combat aircraft applications.         infrastructure requirements. Hindalco
existing industrial infrastructure                                                    is further advocating for a similar
requires augmentation and/or                   Stretching machines of appropriate     build-up of infrastructure through a
upgradation (wherever necessary)            capacities to stretch rolled products     joint government-private partnership.
for the production of a majority            ranging from thin sheets (t = 0.5         As realised by all concerned, such
of the components required for              mm) to thick plates (t = 180 mm)          infrastructure is indeed critically
indigenously built combat aircrafts.        are, therefore, required. These           required for the development and
This is because the dimensions and          equipments should be associated           indigenisation of speciality, wrought
the surface quality requirements of the     with suitable homogenisation and          aluminium alloys in the country.

  DRDO Monograph Series

   Composite Armour Materials and Modules

   Dr T Balakrishna Bhat, former Scientist ‘G’, DMRL and Dr Vemuri Madhu,
Scientist ‘G’, DMRL.

   This monograph deals with the design of protective armour and appropriate
modules to withstand the impacting objects. The monograph systematically
describes an overview of the general principles of armour design, ballistic testing
standards for composites, an introduction into ceramic and polymer materials,
their processing and design concepts related to their use in developing practical
armour systems.

   Price : INR Rs 1000, US $ 20 UK £ 17
   ISBN 978-81-86514-90-0

Aluminium Alloy Technologies for Advanced Defence Systems  	 January-February 2018 15
   10   11   12   13   14   15   16   17   18   19   20