Properties Of Metal Matrix Research Articles

Microstructurally stable nanocomposite WTaMoNb/Cu prepared by mechanical alloying and hot pressing sintering

Refractory high entropy alloys (HEAs) have excellent thermal stability, good strength and toughness, which have great potential application as a second phase in improving microstructure and properties of metal matrix. Here, refractory HEA WTaMoNb is introduced into Cu matrix to synthesize WTaMoNb/Cu nanocomposite by two-step mechanical alloying (MA) and hot pressing sintering (HPS), which owns BCC/FCC structure. During MA, WTaMoNb is firstly prepared and then milled with Cu. Then, WTaMoNb/Cu nanocomposite is synthesised via HPS. The sintered Cu-10wt.%WTaMoNb alloy displays an excellent thermal stability, a high tensile strength of 758.3 ± 20.8 MPa, and an electrical conductivity of 42.5 ± 1.5% international annealed copper standard (IACS).

Production, Structurization, and Properties of Wear-Resistant ‘Iron–Carbon Alloy–Granular Hardmetal Reinforcement’ Materials

The production, structurization, and resultant properties of metal matrix ‘iron–carbon alloy–granular hardmetal reinforcement’ materials are studied. The vacuum suction method ensures almost complete filling of interparticle voids with molten metals and results in composites containing hardmetal reinforcement with 0.17–0.7 mm particles. The composites show the microstructure that has no pronounced transition zone at the hardmetal–metal interface and has a ‘granular’ austenitic cast iron matrix and a significant amount of lamellar graphite. The mechanical properties and abrasive impact wear resistance of the white cast iron and carbon steel materials are examined. The optimum combination of properties is exhibited by the composite consisting of steel 45 and 60 vol.% KKhNF15 hardmetal.

Ultrasonic machining and fretting wear of synthesized duplex brass metal matrix

Abstract In recent years, the budding researchers have an unquenchable desire to highlight the demand and properties of metal matrix by doing commendable researches. The demands of multipurpose metal matrixes are rapidly increasing due to its excellent properties. The phase structure plays an important role in metal matrix. The material properties and characterization is improving based on the phase structure of the material. The present work describes two phases namely soft and hard phase in brass metal matrix which has been fabricated through stir casting process. The material characterization and properties have been studied. The morphology of the material structure has been analyzed through Scanning Electron Microscope (SEM) and material composition has been proved by Energy Dispersive Analysis of X-rays (EDAX). The duplex phase in this metal matrix provides better material properties like strength, hardness, tensile strength and impact strength. Due to dual phase, it is difficult to machine by conventional machining process. Hence, ultrasonic machining process is used for machining this metal matrix. During machining, the various input parameters such as power rating, slurry concentration and grit size have been considered. The material removal rate (MRR) and surface roughness (SR) have been considered as output parameters. The wear properties have been also evaluated by tribometer. The most influential parameter for ultrasonic machining process and wear test has been confirmed through analysis of variance (ANOVA).

Microstructure and properties of metal matrix compositel/stainless steel friction joints containing silver interlayers

Microstructure and properties of metal matrix compositel/stainless steel friction joints containing silver interlayers

Microstructure and properties of metal matrix compositel/stainless steel friction joints containing silver interlayers

The influence of a silver interlayer and friction joining parameters on the microstructure and mechanical properties of friction joints between aluminium based metal matrix composite (MMC) and AISI 304 stainless steel substrates is investigated. The highest notch tensile strength properties were obtained in MMC/Ag/304 stainless steel and MMC/304 stainless steel joints produced using high friction pressure. The introduction of silver during MMC/304 stainless steel friction joining promoted the formation of a veined microstructure containing a mixture of silver, an intermetallic phase, and entrained Al203 (the intermixed region). A second microstructure, the plastic deformed region, consisted of a fine grained dynamically recrystallised MMC matrix including granular silver, Ag3Al, and reinforcing particles. The intermetallic Ag3Al formed as a result of mechanical mixing very early in the friction joining operation. The beneficial effect of using high friction pressure during friction joining was related to the formation and retention of microstructures containing Ag3Al.

A TEM investigation of silicon nitride whiskers

Ceramic fibers are being used to improve the mechanical properties of metal matrix and ceramic matrix composites. This paper reports a study of the structural and other microstructural characteristics of silicon nitride whiskers using both conventional TEM and high resolution electron microscopy.The whiskers were grown by T. E. Scott of Michigan Technological University, by passing nitrogen over molten silicon in the presence of a catalyst. The whiskers were ultrasonically dispersed in chloroform and picked up on holey carbon grids. The diameter of some whiskers (<70nm) was small enough to allow direct observation without thinning. Conventional TEM was performed on a Philips EM400T while high resolution imaging was done on a JEOL 200CX microscope with a point to point resolution of 0.23nm.