Knowledge Resources

Porosity is the most common defect in copper alloy investment castings — but it is not a single defect. Gas porosity, shrinkage porosity, interdendritic porosity, air entrapment, and oxide-related porosity have different causes, different visual signatures, and require different detection methods. Identifying which type is present is the first step to solving the problem. This guide covers all five types, their causes by copper alloy family, & the inspection methods that dete

Aluminium bronze investment casting spans nine ASTM casting grades, from the general-purpose C95400 (AB1) to the marine-standard C95800 (AB2) and the high-performance C95520 specified to AMS 4881 for aerospace landing gear. Grade selection matters. Heat treatment condition matters more. This guide covers all nine grades with US and European standard cross-references, what heat treatment does to aluminium bronze microstructure, and the applications where each grade is the corr

Most high-strength copper alloys sacrifice conductivity for strength. Most high-conductivity copper alloys sacrifice strength for conductivity. Copper Chromium Zirconium — CuCrZr, UNS C18150 — does neither. This guide covers the investment casting of CuCrZr, the applications where its unique combination of 80–85% IACS and 400–500 MPa yield strength makes it the only correct specification, the mandatory heat treatment sequence, and how it compares to the alternatives.

OFHC and ETP copper are both high-conductivity grades used in investment casting, but their oxygen content makes them suitable for different applications. ETP copper is ideal for standard electrical components, while OFHC copper is essential for hydrogen-rich, high-temperature, and vacuum environments where hydrogen embrittlement and outgassing risks must be avoided. This guide compares properties, casting requirements, and specification standards.

Engineers specifying copper bus bars and bus bar connectors have five manufacturing routes to choose from. This guide compares extrusion, machining from billet, CNC bending, sand casting, and investment casting — with a decision matrix and guidance on when converting existing sand castings or permanent mould castings to investment casting delivers measurable improvements in conductivity, surface finish, and material efficiency.

Investment cast copper alloys — ETP, OFHC, CuCr, and CuCrZr — are the engineering standard for switchgear contacts, bus bar connectors, and terminal lugs. This guide covers alloy selection, arc erosion resistance, MV vs. HV requirements, and the quality documentation switchgear manufacturers need from a casting supplier.

Not all copper alloy investment castings are equal — and neither are the foundries that produce them. This guide covers alloy selection across high copper, brass, bronze, and cupronickel families, process control requirements, applicable ASTM standards, and industry applications. Use it to specify correctly, ask better questions, and identify a foundry with genuine metallurgical expertise.

Nickel Aluminium Bronze investment castings in C95500 (AB1) and C95800 (AB2) are the marine engineer’s default specification for components in continuous seawater service — seawater pumps, valve bodies, offshore hardware, and naval components. This guide covers the AB1 and AB2 grade designations and their ASTM, BS, EN, and military equivalents, microstructure behind NAB’s marine performance,

Vacuum investment casting of OFHC copper delivers oxygen below 10 ppm with documented verification — but only when the casting process itself maintains an oxygen-controlled environment throughout melt and pour. This guide covers where OFHC copper is mandated rather than merely preferred, the two OFHC grades (C10100 and C10200) and what they deliver for each application, how to specify correctly on a purchase order, and what certificates to request from a supplier.