<PAGE>
 
                                                                   EXHIBIT 10.45

                             AMENDMENT OF SUBLEASE
                             ---------------------
                                        

     THIS AMENDMENT OF SUBLEASE ("Amendment") is made and entered into as of
March 26, 1998, by and between RAYCHEM CORPORATION, a Delaware corporation
("Sublessor"), and MEMRY CORPORATION, a Delaware corporation ("Sublessee").

                                R E C I T A L S:
                                - - - - - - - - 

     A.  Sublessor and Sublessee have heretofore entered into that certain
Sublease dated of June 28, 1996 ("Sublease"), pursuant to which Sublessor leased
to Sublessee certain premises more particularly described therein ("Subleased
Premises").  Sublessor leases the Subleased Premises from 4065 Associates, a
California partnership ("Master Lessor") pursuant to the Lease (as defined in
the Sublease).

     B.  Sublessor and Sublessee now desire to amend the Sublease on the terms
and provisions contained in this Amendment.  Except as otherwise defined herein,
capitalized terms used in this Amendment shall have the meanings given to such
terms in the Sublease.

     NOW, THEREFORE, Sublessor and Sublessee hereby agree to amend the Sublease
as follows:

     1.  Option to Extend.  Sublessor hereby grants to Sublessee the option to
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extend the Sublease Term for one additional three (3) year period ("Renewal
Term"), which shall commence on October 1, 1998 and end on September 30, 2001,
on all of the terms and provisions contained in the Sublease, except that the
monthly rental payable under the Sublease shall be in the amount provided for in
Section 2 below, and except that Sublessee shall have no further option or right
to extend the Sublease Term.  By its execution of this Amendment, Sublessee
hereby exercises such option to extend. Sublessor shall exercise its option to
extend the term of the Lease under Section 2.5 thereof, and shall use diligent,
good faith efforts to cause the term of the Lease to be extended in accordance
with such exercise by Sublessor.  Notwithstanding the foregoing, if despite
Sublessor's exercise of its option to extend the term of the Lease, and if
despite Sublessor's use of diligent, good faith efforts to cause the term of the
Lease to be extended, the term of the Lease shall not be extended, or Master
Lessor shall claim that the term of the Lease has not been extended, then this
Sublease shall expire at the end of the Sublease Term.  As used in the Sublease,
the term "Sublease Term" shall mean the Sublease Term as the same may be
extended pursuant to the provisions of this Section 1, as applicable.
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     2.  Renewal Term Rent.  If Sublessee shall validly extend the Sublease
         -----------------                                                 
Term, the monthly rental payable by Sublessee to Sublessor under the Sublease
for the Renewal Term shall be equal to the monthly rental payable by Sublessor
to Master Lessor under the Lease for the extended term of the Lease ("Master
Lease Rental").  The Master Lease Rental shall be determined by Sublessee (if
Master Lessor permits and, in any event, with the participation of Sublessor)
and Master Lessor in accordance with the provisions of Section 2.5(B) of the
Lease.  Sublessee and Sublessor shall keep each other apprised of all
significant developments in the rent negotiations with Master Lessor, and if the
monthly rental is determined by arbitration pursuant to Section 2.5(B) of the
Lease, Sublessee shall have the right to designate the qualified real estate
appraiser to be selected by Sublessor, subject to Sublessor's prior written
consent, which shall not be unreasonably withheld or delayed.  During the
Renewal Term, Sublessee shall also remain obligated to pay to Sublessor or to
the appropriate party therefor all other amounts payable by Sublessor to Master
Lessor under the Lease, including, without limitation, all amounts payable under
Sections 5.1, 10.5 and 11.4 and Article 15 of the Lease.

     3.  Indemnity.  Sublessee acknowledges and agrees that Sublessor would not
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exercise Sublessor's option to extend the term of the Lease unless Sublessor
were obligated to do so under Section 1 above, and that Sublessor's exercise of
such option to extend will expose Sublessor to substantial liabilities, costs
and expenses, including, without limitation, rental, real property taxes,
insurance premiums, operating expenses and repair and maintenance obligations
under the Lease during the extended term of the Lease.  Accordingly, in
consideration for Sublessor's entering into this Amendment, Sublessee agrees to
indemnify, defend (with legal counsel acceptable to Sublessor) and hold harmless
Sublessor, its officers, directors, shareholders, employees, agents,
contractors, successors and assigns from and against any and all losses, costs,
claims, damages, liabilities and causes of action (including, without
limitation, attorneys' fees and costs and expert witness and consultants' fees
and costs) incurred by Sublessor and arising out of or in any way connected with
the extension of the term of the Lease beyond its September 30, 1998 expiration
date.  Sublessee's indemnification obligations under this Section 3 shall
expressly extend to all obligations of Sublessor under the Lease attributable to
the extended term of the Lease, and to all claims and liabilities asserted
against Sublessor with respect to the Demised Premises (including, without
limitation, claims or liabilities relating to Hazardous Materials) attributable
to the extended term of the Lease, other than those claims and liabilities due
to the gross negligence or willful misconduct of Sublessor or Master Lessor.

        4.   Limitation on Amendment.  Except as modified by this Amendment, all
of the terms and provisions of the Sublease shall remain in full force and
effect and are hereby ratified and confirmed.

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<PAGE>
 
        5.   Condition.  This Amendment and Sublessor's obligations hereunder
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are expressly conditioned upon the parties' obtaining Master Lessor's written
consent to this Amendment in a form acceptable to Master Lessor, Sublessor and
Sublessee.  If Master Lessor shall fail to provide such written consent to
Sublessor on or before March 30, 1998, Sublessor shall have the right to
terminate this Amendment at any time thereafter by written notice to Sublessee,
provided that Master Lessor has not yet given such written consent to Sublessor.
If Sublessor shall so terminate this Sublease, Sublessee's exercise of its
option to extend the Sublease Term pursuant to Section 1 above shall be of no
force or effect, and this Sublease shall expire at the end of the Sublease Term.

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed
as of the day and year first above written.

SUBLESSOR:                RAYCHEM CORPORATION,
                          a Delaware corporation



                          By /s/ Spencer Leslie
                            -------------------------------
                          Title Director, Site Services
                                ---------------------------


SUBLESSEE:                MEMRY CORPORATION,
                          a Delaware corporation



                          By /s/ James G. Binch
                            ------------------------------
                          Title President and CEO
                                --------------------------

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