This work aims to investigate the feasibility of joining two dissimilar metals,
aluminum 7075 and low-carbon steel SAE1006 plates, with a high-quality weld.. The
processing parameters were different design of Tungsten carbide tool steel (WC) tools,
three dwell times of 15, 17 and 20 sec, and a constant rotational speed of 1250rpm..
The effect of processing parameters on the microstructure, mechanical was
investigated. Results showed that pins increased the microhardness of the upper
aluminum plate significantly. Long pins had greater tensile shear strengths than short
ones because they were influenced by the tool shoulder. Among all factors, tool pin
length had a more noticeable beneficial impact on properties obtained compared to
dwell time. At a high pin length and a 17 dwell duration, the highest temperature
attained was 487°C. The joint interface area was observed using an optical electron
microscope. Mechanical strength tests (lap shear test and micro hardness test) were
carried out to see changes in grain properties through analysis of weld zone’s
microstructure. The tensile shear strength for tools with long pin exceeded that for
short ones due to effect from the tool shoulder region. Brittle mode of fracture was
exhibited by both short and high pins under all conditions used for this research study.
At those conditions which involved a long dwell time under higher pin length,
maximum tensile shear strength recorded was found to be 82.4 MPa. The maximum
micro hardness was 205 HV and was achieved at 20 sec dwell time and using the tool
with longest pin