Microstructure and castability of lead‐free silicon brass alloys

Taha, M. A.; E-Mahallawy, N. A.; Mousa, T. M.; Hamouda, Rawia M.; Yousef, A. F. A. G.

doi:10.1002/mawe.201200932

Cited by 13 publications

(8 citation statements)

References 1 publication

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“…Pb is practically insoluble in Cu and forms discrete particles (precipitates) in cast and wrought (semi)products consisting of two discrete α and β phases. [ 8 ] Nevertheless, annealing at temperatures between 400 and 600 °C followed by quenching can modify the structures to consist of a single phase only (α). [ 9 ] Semi‐products from brasses with Pb addition (leaded brasses), which are usually further subjected to automatic turning to fabricate various final products (decorative features, components of mechanical and electrical appliances such as screws, bolts, nuts, fittings, etc.…”

Section: Introductionmentioning

confidence: 99%

Effects of Temperature (In)homogeneity during Hot Stamping on Deformation Behavior, Structure, and Properties of Brass Valves

Kunčická

Kocich

2021

Adv Eng Mater

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Herein, assessing the effects of initial temperature (in)homogeneity on a hot‐stamped CuZn40Pb2 medical gas valve (fitting) via numerically and experimentally defining mutual relations of selected deformation parameters and optimizing temperature distribution within the original semi‐product heated via induction are focused. For these purposes, three preheating regimes are simulated, and deformation behaviors are evaluated. The predicted results are validated by experimental stamping and subsequent evaluation of the structure and properties of stamped fittings. The results show that preheating the semi‐product with a certain temperature gradient occurring between the axial and (sub)surface regions is favorable, as homogeneous initial temperature distribution results in rapid surface cooling by the effect of heat transfer from semi‐product to die, which imparts inhomogeneous stress distribution, local changes in structural phases, and possible occurrence of oxides. Too low (sub)surface temperature of the semi‐product can result in a significant (local) increase in flow stress, which consequently results in the danger of occurrence of forming defects. The brass fitting stamped with the optimized preheating procedure features an average grain size of 5.8 μm, uniform grains’ orientations with maximum texture intensity of two times random, and ultimate tensile strength of almost 400 MPa, while maintaining elongation to failure of more than 35%.

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Section: Introductionmentioning

confidence: 99%

Effects of Temperature (In)homogeneity during Hot Stamping on Deformation Behavior, Structure, and Properties of Brass Valves

Kunčická

Kocich

2021

Adv Eng Mater

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“…Lead is also useful in the manufacturing process. For example, lead made castability improve in the metal casting method [1,2], and solderability is also improved due to low melting point of lead [3]. Lead has important applications as a solid lubricant, and lead bronze is a useful material for sliding bearings even though there are many regulations as RoHS and REACH and so on.…”

Section: Introductionmentioning

confidence: 99%

Effects of Dispersed Sulfides in Bronze During Sintering

Sato¹

2020

Design and Manufacturing

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Bronze material sintered as sliding bearing is used. In particular, lead bronze is often used because lead acting as a solid lubricant has excellent friction characteristics. However, lead was replaced by another material according to environmental regulations. One candidate for a lead-free material is a sulfide that is well known as a solid lubricant. In this chapter we describe sintering properties and their mechanical properties. First, we investigate chemical components of copper sulfide system and realize stable phase in bronze matrix. After that, we consider the sintering condition of bronze with sulfide dispersed. The sulfides in the bronze may be subject to chemical reduction during sintering, especially when this is carried out under a reducing atmosphere containing hydrogen gas. The effect of the sulfides on the bronze, with a focus on the hardness of the bronze matrix and the reaction between sulfides and hydrogen gas, was investigated. Not only sinterability but also mechanical properties as hardness are discussed.

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“…However, the high price of bismuth and titanium compared to other alloying elements has discouraged any further use. Another possible solution is to substitute lead with silicon although this has been perceived as somewhat reducing the machinability as summarized by Taha et al [8], thus conceivably increasing the manufacturing cost.…”

Section: Introductionmentioning

confidence: 99%

Machinability and manufacturing cost in low-lead brass

Schultheiss

Windmark

Sjöstrand

et al. 2018

Int J Adv Manuf Technol

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Today, commercially used brasses commonly contain 2 to 4 wt% lead. As the availability of low-lead and lead-free brass increases, there are environmental incentives for investigating the consequences of replacing the lead-containing brasses with lead-free equivalents. Generally, lead-free brass is expected to have a lower machinability than its lead-alloyed counterpart, implying a higher manufacturing cost. Thus, the aim of this study has been to quantify the added manufacturing cost by replacing a standard brass alloy with a low-lead alternative. This was done through a case study performed at a Swedish SME which replaced CuZn39Pb3 (3.3 wt% Pb) with low-lead CuZn21Si3P (< 0.09 wt% lead) for a select part. Since CuZn21Si3P is almost twice as expensive as CuZn39Pb3, the material cost was found to have a substantial influence on the manufacturing cost. Additionally, the lower machinability implied a longer cycle time and higher losses while machining CuZn21Si3P, resulting in a 77% overall increase in manufacturing cost when using the low-lead material. Arguably, the difference in material cost, and thus manufacturing cost, may decrease over time making production of low-lead and lead-free brass products a viable option, especially when considering the environmental incentive for decreasing the amount of lead in circulation.

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Microstructure and castability of lead‐free silicon brass alloys

Cited by 13 publications

References 1 publication

Effects of Temperature (In)homogeneity during Hot Stamping on Deformation Behavior, Structure, and Properties of Brass Valves

Effects of Temperature (In)homogeneity during Hot Stamping on Deformation Behavior, Structure, and Properties of Brass Valves

Effects of Dispersed Sulfides in Bronze During Sintering

Machinability and manufacturing cost in low-lead brass

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