Ti STRIP PROPERTIES FABRICATED BY POWDER ROLLING METHOD

In the present study, the characteristics of the Ti powders fabricated by Hydride–Dehydride (HDH) were analyzed in terms of particle shape, size and size distribution. Ti powders were subjected to roll compaction and their microstructure and green densities were evaluated in terms of particle size, powder morphology, roll gap and rolling speed. Effects of blending elements having different powder sizes on densification properties were analyzed. The strip thickness was proportional to the roll gap up to 0.9 mm and the density of titanium strip was decreased with the increase in roll gap. As the roll speed increased, the strip density and thickness were decreased by using -200 mesh Ti powder. However, the effect of rolling speed for -400 mesh Ti powder was not greater than that of -200 mesh powder. The highest density by 93% was achieved by using -400 mesh Ti powder at 0.1 mm roll gap, however edge cracks and alligator cracks were occurred.

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Experimental Investigation and Research on Forming Process of Micro Flat-Wire

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.37-38.417 ◽

2010 ◽

Vol 37-38 ◽

pp. 417-423

Author(s):

Chun Chiu Fok ◽

Zhong Ning Guo ◽

Zhao Qin Yu ◽

Jian Wen He

Keyword(s):

Rolling Process ◽

Rolling Speed ◽

Roll Forming ◽

Wire Surface ◽

Forming Process ◽

Forming Technology ◽

Rolling Method ◽

The Wire ◽

Roll Gap ◽

Control Part

The aim of this study is to get a better understanding of Micro Flat-Wire Roll Forming Technology. There are three methods for Mirco flat-wire forming, i.e., drawing, extrusion, and rolling. Without replacing the equipment, rolling method only demands to adjust the relative roll gap between the pressure and the wire deformation that it can produce different specifications of mirco flat-wire. The rolling equipment was introduced and can be divided into three parts, the mechanism section, the control part and the wire-locating device. Furthermore, the rolling process parameters were summarized as well. The effect of rolling amount and rolling speed on the wire surface quality was also discussed.

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Casting of Al-Mg Strip Using Single Roll Caster Equipped with a Scraper

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.880.49 ◽

2021 ◽

Vol 880 ◽

pp. 49-56

Author(s):

Toshio Haga ◽

Kosuke Tsukuda ◽

Keisuke Oida ◽

Hisaki Watari ◽

Shinichi Nishida

Keyword(s):

Molten Metal ◽

Thickness Distribution ◽

Surface Characteristics ◽

Strip Thickness ◽

Optimal Conditions ◽

Roll Speed ◽

Pouring Temperature ◽

Strip Cast ◽

Cold Rolled ◽

Twin Roll

A scraper was attached to an unequal-diameter twin-roll caster without requiring large modifications. This caster was used as a 1000 mm diameter single roll caster equipped with a scraper, and its strip casting ability was tested. The effects of the scraper angle and load, the roll speed, and the pouring temperature of the molten metal on the scribed surface, thickness distribution and average strip thickness were investigated. The scribed surface characteristics were sound and the thickness distribution was flat when the scraper angle was 60° and the scraper load was in the range of 1 to 4 kg. When the scraper load was more than 1 kg, the thickness distribution was uneven. The average strip thickness decreased as the roll speed increased. The pouring temperature of the molten metal influenced the evenness of the solidified layer thickness. The solidified layer became even as the molten metal temperature was decreased. A strip cast with the determined optimal conditions was then cold rolled down to 1 mm to improve its surface quality.

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Numerical Simulation for Metal Powder Cross Shear Rolling Compaction

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.569.111 ◽

2012 ◽

Vol 569 ◽

pp. 111-115 ◽

Cited By ~ 1

Author(s):

Ming Jun Liu ◽

Guang Chao Liu

Keyword(s):

Metal Powder ◽

Rolling Force ◽

Velocity Ratio ◽

Rolling Speed ◽

Speed Ratio ◽

Force Development ◽

Mechanical Models ◽

Roll Compaction ◽

Calculation Code ◽

Compaction Ratio

Characteristics of cross shear rolling for metal powder roll compaction were analyzed. The finite deformation elasto-plastic constitutive model and corresponding calculation code were derived based on compressible continuum mechanics. Numerical simulations were performed for the cross shear rolling of metal powder. The rolling force development law under different compaction ratio and rolling speed ratio was studied. It showed that the rolling force decreased apparently as differential velocity ratio increased. Comparisons were done between simulations and experiments from references and the reliability of the mechanical models and calculation code derived in this paper were proved.

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Kiss-Point Position Control of Solidification Layer and Process Optimization for Twin-Roll Casting of Magnesium Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.3844 ◽

2011 ◽

Vol 189-193 ◽

pp. 3844-3851

Author(s):

Wen Ping Weng ◽

Kang Deng ◽

Zhong Ming Ren ◽

Qi Chen ◽

Zhi Dong Chi ◽

...

Keyword(s):

Magnesium Alloy ◽

Magnesium Alloys ◽

Process Optimization ◽

Strip Thickness ◽

Alloy Strip ◽

Roll Speed ◽

Twin Roll Casting ◽

Roll Casting ◽

Twin Roll

The solidification and process optimization for twin-roll casting of magnesium alloys have been studied. Effects of roll speed, roller diameter, setback length and strip thickness on the position of the solidification front and the surface quality of strip were analyzed through experiments. A kiss-point model which considers the strip thickness, set-back length and roll speed was established to optimize process and enhance the surface quality of magnesium alloy strip. Results showed that the twin-roll casting process could be effectively stabilized and optimized under the direction of the model, and the defectless magnesium alloy strip was obtained.

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Roll Eccentricity Phase Identification System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.562-564.987 ◽

2012 ◽

Vol 562-564 ◽

pp. 987-992

Author(s):

Yang Yang ◽

Yi Qun Wang ◽

Zeng Wang Zhang

Keyword(s):

Rolling Force ◽

Rolling Speed ◽

Detection Methods ◽

Identification System ◽

Phase Identification ◽

Phase Detection ◽

Disturbance Compensation ◽

Rolling Velocity ◽

Direct Measurements ◽

Roll Gap

Roll eccentricity is widespread in the strip mill, has cyclical impact on strip thickness, so disturbance compensation is required to improve the product quality. The key step of disturbance compensation is to obtain reliable roll eccentricity signal. Existing direct measurements of roll eccentricity signal method requires special equipments with high precision but not practical enough. There are few detection methods which including rolling velocity. Roll eccentricity signal is difficult to directly measured, should fuse many kinds of detectable signal to be extracted through the data analysis which includes rolling force, roll gap, incoming thickness of rolled piece, exit thickness, tension, and so on. This paper puts the four high mill as an object, according to the influence of the main factors of roll eccentricity ——backup-roll eccentricity for analysis, develops a Roll Eccentricity Phase Identification System. This system extracts from amplitude of eccentricity signal, combines eccentricity signal’s frequency with phase through roll segmentation marker integrating rolling speed, according to its cyclical change law to achieve the signal calibration by testing amplitude characteristics to determine the phase of roll eccentricity of the current rolling area. After determining the signal phase, detect the phase of eccentricity signal according to integration of rolling speed, and through phase detection to ensure the reliability of the detectable phase. This system is verified by the experiment in four high mill, the results show that the method of phase detection of eccentricity is effective, it provides a simple and effective new way for the phase extraction of roll eccentricity signal, and can used in similar condition.

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Characteristics of Powder-Rolled and Sintered Sheets Made from HDH Ti Powders

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.520.281 ◽

2012 ◽

Vol 520 ◽

pp. 281-288 ◽

Cited By ~ 8

Author(s):

Nho Kwang Park ◽

C.H. Lee ◽

Jeoung Han Kim ◽

Jae Keun Hong

Keyword(s):

Cold Rolling ◽

Relative Density ◽

Tensile Properties ◽

Process Parameters ◽

Annealing Treatment ◽

Powder Rolling ◽

Powder Size ◽

Thin Sheets ◽

Roll Speed ◽

Roll Gap

In this study, direct powder rolling was applied to make thin sheets from HDH (hydrogenation and dehydrogenation) powders. Effects of materials and process parameters on tensile properties of sintered sheets are investigated. In the direct powder rolling with two-horizontal counter-rotating rollers, materials parameters including powder size and process parameters such as roll gap, roll speed, and packing height are controlled. With -100mesh Ti powders, CP titanium sheets of a thickness up to 1.5mm and a width up to 300mm were obtained without any rolling defects. Sintering of the rolled strips was performed between 1000°C and 1250°C at 50°C intervals for 1hour to 4 hours. The relative density of the sintered strips was found to be around 85 to 90 percent. After sintering, the complete densification was made by cold rolling, and microstructures and tensile properties were evaluated after annealing treatment at 750°C for 2 hours.

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Factors Affecting Curling in Rolled Sheet

Journal of Engineering Materials and Technology ◽

10.1115/1.3443129 ◽

1973 ◽

Vol 95 (2) ◽

pp. 103-106 ◽

Cited By ~ 3

Author(s):

C. R. Heiple

Keyword(s):

Leading Edge ◽

Reduction Ratio ◽

The Other ◽

Rolled Sheet ◽

Roll Speed ◽

Factors Affecting ◽

Height Reduction ◽

Bottom Roll ◽

Increasing Temperature ◽

Roll Gap

The influence of several rolling parameters on curling during the rolling of sheet was investigated. The material studied was primarily 0.5 in. thick 2024 aluminum. The factors studied were different top and bottom roll diameters, differential strength through the thickness of the sheet, lubrication, roll-table height, reduction ratio, temperature, roll speed, and a beveled leading edge. The sheet curled toward the smaller roll, away from the better lubricated side, toward the strong side if one side was stronger than the other, and up when the entrance roll table was too high. Curling increased for greater reductions (under the conditions studied) and also increased slightly with increasing temperature. Curling was not sensitive to roll speed or a beveled leading edge. The curling observed can generally be explained on the basis of a shear in the roll gap because of different locations of the neutral points along the arcs of contact for the two rolls. Curling observed when one side of the sheet is significantly softer than the other appears to be due to greater elongation of the soft side during rolling.

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FABRICATION OF POROUS Ti- AND W-COMPACTS BY ELECTRO-DISCHARGE-SINTERING PROCESS

Surface Review and Letters ◽

10.1142/s0218625x10014004 ◽

2010 ◽

Vol 17 (02) ◽

pp. 245-250 ◽

Cited By ~ 3

Author(s):

GI-AN SONG ◽

JI-SEON SHIN ◽

TAE-JU KANG ◽

HAN SHIN CHOI ◽

JIN KYU LEE ◽

...

Keyword(s):

Size Range ◽

Single Pulse ◽

Hardness Measurement ◽

Heterogeneous Structure ◽

Powder Morphology ◽

Porous Ti ◽

Particle Bonding ◽

Microstructure Examination ◽

Porous Microstructure ◽

Ti Powder

A single pulse of 0.57–1.1 kJ/0.3 g-spherical Ti -powder in size range of 30–70 μm, using a constant 450 μF capacitor, was applied to produce fully porous Ti - and W -compacts by electro-discharge sintering. Microstructure examination and hardness measurement of the porous Ti -compacts revealed that more stable necks formed with increasing electrical input energy up to 1.1 kJ. On the contrary, W -compacts using rectangular W -powders in size range of 5–15 μm are composed of solid region with micropore and porous layer with weak particle bonding indicating heterogeneous structure. These results suggest that the powder morphology plays a crucial role to control the porous microstructure.

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