Effect of Thickness of Interlayer on Microstructures of PM TC4 and GCr15 Joints Prepared by HIP Diffusion Bonding
Using different thickness of pure nickel as interlayer, hot isostatic pressing (HIP) diffusion bonding between TC4 prealloyed powders and GCr15 bearing steel have been performed at the temperature of 850 ℃, under pressure of 150 MPa for 2 hrs. The diffusion bonding joints gained have been observed and analyzed by optical microscopy, electron microprobe and X-ray diffraction. The result of observation by optical microcopy indicates that, at the interface of TC4 and interlayer, many connecting arcs have been formed, and these arcs gradually disappear with thickness of pure nickel increasing. The result of observation by electron microprobe reveals that, during the process of HIP diffusion bonding, nickel atoms have a short diffusion distance in the zone of GCr15, whereas they diffuse a comparatively long distance in zone of TC4. The observation also find that the distributions of elements of titanium, iron and chrome vary in different area of zone of pure nickel, which results in the formation of different type of intermetallics. Thus, the contact of titanium atom and iron atom can be avoided with certain thickness of pure nickel as interlayer. When thickness of interlayer is large than 120 um in this test, the combination of titanium atom and iron atom will be avoided and intermetallics such as TiFe and TiFe2, are disappeared. These rules mentioned above also have been confirmed by the analysis of X-ray diffraction.
thickness of interlayer microstructure HIP diffusion bonding P/M titanium alloy TC4 bearing steel GCr15
LANG Zebao WANG Liang JIA Wenjun
Aerospace Research Institute of Materials & Processing Technology, Beijing 100076, PR China
国际会议
沈阳
英文
899-904
2011-11-22（万方平台首次上网日期，不代表论文的发表时间）