scispace - formally typeset
Search or ask a question
Topic

Alloy

About: Alloy is a research topic. Over the lifetime, 171884 publications have been published within this topic receiving 1719420 citations. The topic is also known as: alloys.


Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, the chemistry at scale/metal interfaces was studied using scanning Auger microscopy after removal of the scale in ultra-high vacuum using an in situ scratching technique, and the adhesion of these scales was determined qualitatively by way of micro-indentation and scratching on the surface oxide.
Abstract: The chemistry at scale/metal interfaces was studied using scanning Auger microscopy after removal of the scale in ultra-high vacuum using an in situ scratching technique. Al2O3 and Cr2O3 scales formed between 900°C and 1100°C on Fe-18 wt.% Cr-5 wt.% Al and on Ni-25 wt.% Cr alloys, respectively, were investigated. The adhesion of these scales was determined qualitatively by way of micro-indentation and scratching on the surface oxide. All of the alumina scales fractured to the same degree to expose the metal surface, regardless of the oxidation temperature. The chromia-forming alloy on the other hand, developed more adherent scales at lower oxidation temperatures. About 20 at.% sulfur was found at the metal surface in all cases, and its presence was not only detected on interfacial voids, but also on areas where the scale was in contact with the alloy at temperature. Results from this study clearly demonstrated that sulfur as an alloying impurity does segregate to the scale/alloy interface. However, for alumina scales and chromia scales, the effect of this segregation on oxide adhesion is noticeably different.

172 citations

Journal ArticleDOI
TL;DR: In this paper, several mixtures of self-fluxing NiCrBSi alloy powder and a nickel-clad WC powder (10 wt.% Ni and balance WC) were laser cladded on stainless steel substrates of austenitic type (AISI 304).
Abstract: In this work, several mixtures of self-fluxing NiCrBSi alloy powder and a nickel-clad WC powder (10 wt.% Ni and balance WC) were laser cladded on stainless steel substrates of austenitic type (AISI 304). The aim of the study was to determine the influence of the volume fraction of the reinforced WC particles on the formation and performance of the composite layer. The effect of other parameters of the treatment, such as the laser energy, beam profile, traverse speed and the mass rate of the feed powder was also investigated. Clad layers of 0.5–1.5 mm height were obtained, its microhardness measured and the microscopic morphology and distribution of tungsten carbide particles within the layer characterized by scanning electron microscopy (SEM). It was found that most clad layer properties such as its porosity, microhardness and homogeneity are determined by the percentage of WC particles in the mixture. Pores were observed for volume fractions roughly above 50%. Below this limit, homogeneous, dense and crack free clad layers were obtained, with measured hardness ranging between 600 and 1000 HV depending on the WC content.

172 citations

Journal ArticleDOI
01 Oct 1995-Langmuir
TL;DR: In this paper, the optical spectra and HRTEM were used to obtain phase-separated composites of silver and copper, whose observed spectra are very similar to the theoretical spectra of silver/copper alloy particles.
Abstract: Ultrafine metal particles (copper, silver, and gold) have been prepared by UV irradiation of their salts dissolved in ethanol. The photoreduction of their metal salts is greatly accelerated by using benzoin as a photoinitiator. Highly dispersed copper and silver particles are obtained through the photoreduction. In the case of gold, the average diameter of the gold particles increases from 7 to 17 nm with increasing benzoin concentration. This method has been applied to obtain silver/copper and silver/gold composite particles. The optical spectra and HRTEM show that the silver/copper composite particles are phase-separated composites of silver and copper, whose observed spectra are very similar to the theoretical spectra of silver/copper alloy particles. In the silver/gold system, the observed spectra are in good agreement with the theoretical spectra of the alloy particles since that the surface plasmon band remains as a single peak and shifts continuously by varying the silver/gold composition. This strongly suggests the formation of silver/gold alloy particles.

172 citations

Journal ArticleDOI
TL;DR: In this article, the phase composition and electrochemical performances of microarc oxidation (MAO) films formed on AZ91D alloy using step-down current method in phosphate electrolytes (P-film) and silicate electrolytes(Si-film).
Abstract: This paper reports on studies of the phase composition and electrochemical performances of microarc oxidation (MAO) films formed on AZ91D alloy using step-down current method in phosphate electrolytes (P-film) and silicate electrolytes (Si-film). The results showed that the P-film was mainly composed of Mg, MgAl 2 O 4 , MgO and the Si-film was composed of Mg 2 SiO 4 , MgO. There clearly existed a fluoride-enriched zone of about 1∼2 μm for P-film and 0.7∼1 μm for Si-film at the MAO coating/substrate interface. The electrochemical tests showed that both P-film and Si-film could enhance the corrosion resistance of AZ91D magnesium alloy significantly; the corrosion failure processes of the two films in 5 wt.% NaCl solution were quite different.

172 citations

Journal ArticleDOI
TL;DR: In this article, a new Ni-based bulk glassy alloys with high strength and good ductility were synthesized for the first time in Ni- Nb-Ti-Zr base system by the mold-clamp or copper mold casting method.
Abstract: New Ni-based bulk glassy alloys with high strength and good ductility were synthesized for the first time in Ni- Nb-Ti-Zr base system by the mold-clamp or copper mold casting method. The bulk glassy Ni 53 Nb 20 Ti 10 Zr 8 Co 6 Cu 3 alloy has a rod shape with diameters up to 3mm or a sheet shape with thickness up to 1 mm. The glass transition temperature (T g ) and the supercooled liquid region defined by the difference between T g and crystallization temperature (T g ). ΔT x (= T x - T g ) are 846 and 51 K, respectively, and no distinct change in T g . T x and ΔT x with sample diameter is seen. The Ni-based alloy is located in the vicinity of eutectic composition and has a high reduced glass transition temperature (T g /T m ) of 0.67. The Ni-based bulk glassy alloy also exhibits good mechanical properties. i.e., tensile fracture strength of 2700 MPa, tensile fracture elongation of 2. 1%, compressive fracture strength of 3010 MPa and compressive fracture elongation of 2.4%. It is noticed that the tensile fracture strength is the highest among all bulk glassy alloys developed up to date. The success of synthesizing the new Ni-based bulk glassy alloy with good mechanical properties is promising for future uses as a new type of high strength material.

172 citations


Network Information
Related Topics (5)
Microstructure
148.6K papers, 2.2M citations
96% related
Coating
379.8K papers, 3.1M citations
89% related
Ultimate tensile strength
129.2K papers, 2.1M citations
87% related
Thin film
275.5K papers, 4.5M citations
87% related
Amorphous solid
117K papers, 2.2M citations
87% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202310,509
202220,674
20215,930
20208,500
20199,616
20189,122