Building Technology 5 Division 5 Metals

The given passage describes pre-fabricated units that are manufactured for the exterior and interior of buildings. These units are made of aluminum and come in various widths. The panels for the exterior of buildings are specifically made with an aluminum exterior facing, which can be in the form of a casting, extrusion, or sheet material. Therefore, the correct answer is "ALUMINUM PANELS" as it aligns with the description provided in the passage.

Electroplating is the correct answer because it involves covering aluminum with a protective or decorative film or another metal through the process of electrodeposition. This process ensures that the coating is complete and unbroken, preventing galvanic action that can be destructive to aluminum. Mechanical finishes, chemical finishes, and electrolytic finishes do not specifically involve the process of electrodeposition, making them incorrect answers.

Aluminum can be extruded, meaning it can be shaped into structural forms economically. This makes it a suitable material for structural applications, such as in the construction of buildings, bridges, and other load-bearing structures. Its physical and chemical characteristics make it a desirable choice for these applications, as it is lightweight, corrosion-resistant, and has good strength-to-weight ratio. Therefore, the correct answer is "STRUCTURAL ALUMINUM."

Aluminum foil is the correct answer because it is rolled to a thickness of 0.005", which is considered to be foil rather than sheet. It is commonly used for thermal insulation and vapor barriers. Additionally, it can be laminated to other materials to provide additional insulation. The other options listed, such as aluminum sheet and strip, structural aluminum, and aluminum doors and windows, do not fit the description given in the question.

The correct answer is "ALUMINUM SHEET AND STRIP." This is because aluminum sheet and strip are commonly used for roofing, flashing, gutter, and other applications mentioned in the question. Aluminum foil is typically used for cooking and packaging, while structural aluminum is used for construction purposes. Aluminum doors and windows are specifically mentioned as a separate category. Therefore, the most appropriate choice is aluminum sheet and strip.

Chemical finishes are based on chemical reactions with the aluminum surface to achieve various results such as etching, cleaning, or polishing the surface to remove oxide film or surface irregularities. These finishes provide a design, clean surface texture, or polished effect. They can also involve oxidizing the surface with aluminum or other metallic oxides, which serve as a protective layer or a base for subsequent treatment. However, chemical finishes have limited color options compared to electrolytically-applied oxide films obtained through anodization.

Aluminum is the correct answer because it is a soft, nonmagnetic silvery metal that has a low melting point, high thermal and electrical conductivity, and a moderately high coefficient of expansion. It is also known for its light weight, being one-third that of iron, brass, or copper. Aluminum's properties make it a versatile material used in various industries, including construction, transportation, and packaging.

Paint can be applied as a finish to aluminum surfaces that have been prepared by a suitable chemical treatment. This means that before applying the paint, the aluminum surface needs to be treated with a chemical process to ensure proper adhesion and durability of the paint. It is important to note that lead-based paints should not be used on aluminum surfaces.

The given question states that various items like rods, bars, pipes, railings, fittings, and special shapes are manufactured as stock items for ornamental design purposes. The correct answer, "Ornamental aluminum," aligns with this information as it suggests that aluminum is one of the materials used for creating these decorative items.

Electrolytic finishes are the correct answer because the passage mentions that anodized finishes are based on the ability of aluminum to develop a protective coating of oxide on its surface. This process involves the use of electrolysis, where an electric current is passed through an electrolyte solution to create the protective coating. Therefore, electrolytic finishes are the most suitable option based on the information provided.

The given description mentions that the material is a sheet made of a special aluminum alloy, designed for roofing and siding. It also states that it consists of an aluminum alloy core clad with another highly corrosion-resistant aluminum. Based on these details, the most suitable option is "CORRUGATED ALUMINUM." Corrugated aluminum sheets are commonly used for roofing and siding purposes due to their durability, strength, and resistance to corrosion.

The given correct answer, "ALUMINUM DOORS AND WINDOWS," fits the description provided in the question. The question states that the items are "fabricated from extrusions and rolled shapes," which is a common manufacturing process for aluminum doors and windows. This suggests that these items are made from aluminum and are formed using these techniques. Therefore, the answer aligns with the information given.

ALCLAD is a term used to describe a protective coating applied to thin sheets of an aluminum alloy. This coating is primarily applied to enhance corrosion resistance, as the alloy's resistance has been decreased by the addition of certain constituents for strength and other properties. The cladding not only provides protection against corrosion but also improves the overall appearance of the alloy.

Porcelain or Vitreous Enamel is the correct answer because it is a finish that forms a hard, resistant surface. It is also available in a broad color range, creating a different feeling compared to anodic color, which is metallic in nature. This suggests that Porcelain or Vitreous Enamel is a suitable option for achieving a glassy, non-metallic finish.

The given answer, "Mechanical finishes," is the correct answer because it states that aluminum finishes can be achieved through grinding, polishing, scratching, sandblasting, embossing, or other treatments of the surface. These methods involve physical manipulation of the surface to achieve the desired effect or provide a base for other finishes. This distinguishes mechanical finishes from chemical finishes, electrolytic finishes, and electroplating, which involve different processes or treatments to achieve the desired result on the aluminum surface.

A sandwich panel is a type of construction that consists of two outer layers, called skins, that are bonded to a central core material. The skins provide the structural integrity and protection to the panel, while the core material adds insulation and strength. Therefore, the correct answer is "skin construction" as it accurately describes the construction method of a sandwich panel.