SEM and XRD Characterization of Ni-Hf Alloys at Low Hf Concentration

SEM and XRD Characterization of Ni-Hf Alloys at Low Hf Concentration

The alloying and phase formation in Ni-Hf samples with 0.2-, 2-, and 5-at.% Hf were studied by X-ray diffraction (XRD) technique and scanning electron microscopy (SEM). Both characterization methods, XRD and SEM, reveal the presence of the HfNi5 phase (fcc structure) where the excess Ni atoms are present in the form of Ni or Ni-rich segregations in the sample containing 5-at.% Hf. The sample wi...

Glassy and icosahedral phases in rapidly solidified Ti–Zr–Hf–(Fe, Co or Ni) alloys

The icosahedral quasicrystalline, amorphous plus crystalline and glassy phases were formed in Ti40Zr20Hf20(3d-LTM)20 alloys (3d-LTM=3d late transition metals Fe, Co and Ni). The icosahedral phase formed in the melt-spun Ti40Zr20Hf20Fe20 alloy is metastable and the average size of the quasicrystalline icosahedral particles precipitated in the amorphous matrix is 5 nm. The metastable icosahedral ...

Analysis of Ti - Ni - Hf shape memory alloys by combinatorial nanocalorimetry

CHARACTERIZATION OF THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF LIQUID PHASE DIFFUSION BONDS USING EUTECTIC Ni-Hf AND Ni-Zr BRAZE ALLOYS AFTER SHORT PROCESSING TIMES (40 MINUTES)

As shown in the preceding chapter, simple binary eutectic Ni-Hf and Ni-Zr braze alloys can be used to successfully join In738 Ni-base superalloy. The joint gap must, however, be narrow (less than 0.15 mm in width) to allow capillary action to draw the filler metal into the joint. Such narrow joint gaps are usually only found in the manufacturing industry. In the repair industry, especially in I...

Hf Concentration Control in Ic Manufacturing

The etching of SiO2 layers from silicon surfaces is one of the most critical steps in wet processing technology. Although numerous studies have been performed to analyze the mechanisms and kinetics of these processes, little attention has been given to monitoring and controlling the chemical concentrations in the process baths. Chemical concentration control is becoming crucial to wafer process...