Fatigue crack propagation tests were conducted on the powder metallurgy nickel-base superalloy KM4 at room temperature. Two different heat treatments were investigated, one which produced a relatively coarse grain size around 55 μm, and another which produced a very fine grain size around 6 μm. Tests were conducted at 50 Hz and 1000 Hz in an advanced servohydraulic testing machine at R-ratios b...

Since the first laboratory experiments of M. Carey Lea and the original definition by F. W. Ostwald at the end of the 19th century, mechanochemistry, a field treating chemical changes induced in substances as a result of applied mechanical stress, has been evolved as an important area of chemistry from the viewpoint of both the fundamental research and applications (Takacs, 2004; Boldyrev & Tka...

The oxidation behavior of two types of inhomogeneous nickel was investigated in air at 1273 K for a total oxidation time of 100 h. The two types were porous sintered-nickel and microstructurally inhomogeneous cast-nickel. The porous-nickel samples were fabricated by compacting Ni powder followed by sintering in vacuum at 1473 K for 2 h. The oxidation kinetics of the samples was determined gravi...

Inertia friction welded joints often present different microstructures than the base metal, and subsequent heat treatment processes are always needed to maintain superior performance. This study investigates effect of semi-aging after welding on microstructure, residual stress, micro-hardness, tensile properties inertia FGH96 powder metallurgy superalloy using optical microscopy, scanning elect...

Automotive and aerospace industries are required to light materials which have high properties. This causes to reduce production cost and fuel consumption. One of these advanced materials that have been attracted at these decades is particulate metal matrix nanocomposites. These materials have a combination of ductile matrix alloy properties and ceramic reinforcement nanoparticles. Powder metal...

In this paper, the powder metallurgy (P/M) Ni-based superalloy FGH4096 with an incomplete dynamic recrystallization structure was treated by a solution treatment at different temperatures, cooling methods, and holding times. The size, morphology, distribution of grains γ′ precipitates were characterized optical microscope (OM) scanning electron (SEM). Research results showed that increase tempe...

Segregation and chemical inhomogeneity are well-known problems in powder metallurgy and are also an issue for new applications of powder mixtures, for example as starting materials for severe plastic deformation. In this study, Cu-coated Fe powder was prepared via immersion deposition, inductively hot-pressed and subsequently deformed using high-pressure torsion. The homogeneity of the pressed ...

Despite the ongoing progress in metallurgical characterisation of machined surfaces, knowledge thermal conditions under which they originate during workpiece-flank interaction is still lacking. When cutting advanced superalloys, little known about temperature evolution part volume, where workpiece material interacts with tool flank. In this work, characteristics field and resulting surface meta...