Match each alloy listed on the left with its characteristic elemental composition and prim… — JAMB UTME

Match each alloy listed on the left with its characteristic elemental composition and primary application on the right.

Duralumin $\text{Al}$ , $\text{Cu}$ , $\text{Mg}$ , and $\text{Mn}$ ; lightweight with high tensile strength used in aircraft construction.
Brass $\text{Cu}$ and $\text{Zn}$ ; malleable and corrosion-resistant alloy used in decorative fittings and musical instruments.
Stainless Steel $\text{Fe}$ , $\text{Cr}$ , $\text{Ni}$ , and $\text{C}$ ; highly resistant to rusting and used for surgical instruments and cutlery.
Soft Solder $\text{Pb}$ and $\text{Sn}$ ; possesses a low melting point used for joining electrical components.

Duralumin pairs with

\text{Al}

\text{Cu}

\text{Mg}

\text{Mn}

(aircraft construction); Brass pairs with

\text{Cu}

\text{Zn}

(musical instruments/fittings); Stainless Steel pairs with

\text{Fe}

\text{Cr}

\text{Ni}

\text{C}

(cutlery/surgical tools); Soft Solder pairs with

\text{Pb}

\text{Sn}

(joining electrical connections).

Each alloy is correctly matched according to its primary constituent elements and application: Duralumin (

\text{Al}

\text{Cu}

\text{Mg}

\text{Mn}

) for aircraft bodywork; Brass (

\text{Cu}

\text{Zn}

) for musical instruments and fittings; Stainless Steel (

\text{Fe}

\text{Cr}

\text{Ni}

\text{C}

) for corrosion-resistant cutlery and medical tools; Soft Solder (

\text{Pb}

\text{Sn}

) for low-temperature electrical joint soldering.

Identify the base metals and secondary additives for light-engineering alloys.

Duralumin is an aluminium-based alloy with

\text{Cu}

\text{Mg}

, and

\text{Mn}

engineered for aerospace applications due to low density and high mechanical strength.

Aluminium provides low mass while added metals induce lattice distortion to increase hardness.

Distinguish between copper-zinc and copper-tin alloys.

Brass is made of copper and zinc, which differs from Bronze (copper and tin). Brass is widely used for decorative fittings and musical instruments.

Zinc substitution in the copper matrix enhances workability and corrosion resistance.

Identify steel variations based on anti-corrosion alloying elements.

Stainless steel contains iron, chromium, nickel, and carbon. Chromium imparts a self-healing passive oxide coating.

Chromium content (typically >10.5%) resists oxidative rusting in moist atmospheric conditions.

Recall low-melting-point joining alloys.

Soft solder is an alloy of lead and tin engineered to melt at relatively low temperatures (

< 250^\circ\text{C}

The eutectic composition of lead and tin depresses the melting point below that of either constituent element.

Elemental compositions, structural properties, and functional uses of key industrial alloys

Soru