The measured solidification range for the bismuth-containing alloy was approximately 90[degrees]F (50[degrees]C) greater than the leaded alloy
solidification range and approximately 81[degrees]F (45[degrees]C) smaller than the lead/bismuth free alloy The liquidus of the bismuth containing alloys was lower than both the leaded and lead/bismuth free alloys.
Occasionally customers request a leaded alloy
, but LA Pump and Valve details the benefits of its "upgraded" alloy and converts the customer to no-lead copper casting.
Chicago Faucet Co, a green sand foundry pouring a copper-base leaded alloy
, employs a reclamation system that reclaims sand and recovers alloy for remelting.
Cross contamination with leaded material is detrimental and is a major concern if bismuth alloys get into leaded alloys
In most cases, few pattern changes are required when switching from leaded alloys
While some existing gating and risering techniques designed for traditional leaded alloys
, such as C83600, were successful without modification, other casting geometries required larger ingates.
also are more castable than their no-lead counterparts.
As new environmental legislation limits the lead content in castings, especially in water applications, more users are demanding non - leaded alloys
for other applications.
Copper-bismuth alloys were developed to behave in the metalcasting process and have properties similar to existing leaded alloys
PANEL: Case Studies in the Use of Solidification Modeling to Transition Away From Leaded Alloys
The lead-free alloys were developed to have foundry characteristics (melting and casting) as well as properties (physical and mechanical) similar to existing leaded alloys
This new rule will force many foundries to begin reporting on lead-especially those melting leaded alloys
or contaminated scrap.