Copper and copper alloys possess a number of superior properties,
such as excellent electrical conductivity, excellent thermal
conductivity and forming property, so that complex components
of the steel, copper and copper alloys have complementary advantages
on the economy and performance [1]. But it is very difficult
to realize the good bonding of them by adopting routine fusion
welding because of a rather large difference in the melting point,
coefficient of thermal conductivity, coefficient of linear expansion
between copper and steel [2]. At present, the high-quality welding
joint was acquired often by adopting vacuum diffusion welding
, diffusion welding of QSn4-4-2.5 alloy and 45 steel using nickel
as interlayer has been reported the joint has a good performance.
It was reported that the plunger of an aero-engine plunger pump
was produced through vacuum diffusion welding of tin bronze and
alloyed steel [1]. But the vacuum diffusion welding equipments are
expensive, the technological requirement is rigorous and the efficiency
is low. As a new solid-state welding technology of materials,
the isothermal superplastic solid-state welding (ISSW) is assumed
to have some advantages, e.g. the simplicity of the process, the low
cost, the ease to realize high-quality solid bonding of the hetero-
geneous materials. Therefore, many studies have been carried out
in solid-state welding methods in recent years. So far, the
number of reports of the superplastic solid-state welding between
non-ferrous alloy and steel is low. Based on the research of
the superplastic of copper alloys and steel , the feasibility of
the isothermal superplastic solid-state welding of 40Cr and QCr0.5,
ZQSn6-6-3 was studied in the paper,with the aim to provide important
test reference to the new solid-state welding of non-ferrous
alloy with steel.