Metals Flashcards

Question

Properties/Characteristics and Uses of Stainless Steel

Answer 1

Properties/Characteristics: - Tough, hard, corrosion resistant. - 18% chrome, 8% nickel - Melting Temp: 1,510°C Uses: - Sinks, kitchenware, cutlery

Answer 2

Properties/Characteristics: - Hard, tough. - 1% Silicon, 0.40-0.55% Carbon, 0.4% Molybdenum, 0.4% Manganese - Melting Temp: 1,427°C Uses: - Blanking punches and dies, extruded dies, fine press tools

Answer 3

Properties/Characteristics: - Good hardness and brittleness, high resistance to corrosion. - 88% copper, 12% tin - Melting Temp: 913°C Uses: - Boats and ships, sculptures, musical instruments, electrical connectors, bearings

Answer 4

Properties/Characteristics: - High corrosion resistance, malleable, susceptibility to cracking under stress, highly castable, good thermal conductivity. - 90% copper, 10% tin - Melting Temp: 930°C Uses: - Decoration, musical instruments, plumbing pipes and tubes

Answer 5

Properties/Characteristics: - Relatively soft, ductile, and workable, lightweight, high strength per unit weight, can be rolled, forged, and extruded. - 90% aluminium, 4% copper, 0.5%-1.0% manganese - Melting Temp: 660°C Uses: - Aircrafts, frames of speed boats, pressure cookers, lightweight guns

Answer 6

Properties/Characteristics: - Good malleability, good ductility, can be easily bent and hammered - 92% tin, 6-7% antimony, and 1-2% copper - Melting Temp: 290°C Uses: - Dishes, church vessels, decorative items, kettles, mugs

Answer 7

- Protecting the material against corrosion - Making the product water repellent - Improving its resistance to wear and light - Improving its ability to reflect or absorb heat - Improving its ability to insulate against heat or electricity

Answer 8

Electrochemical process that allows ions from the coating material to form on the base material, giving it the finish of the coating material. Eg. chromium plating is used to enhance the properties of bathroom taps, kitchen equipment and vehicle components.

Answer 9

Aluminium can be anodised, this process makes the surface of the aluminium more durable and resistant to scratches. Anodising is produced in an electrochemical cell where a sulphuric acid = electrolyte, aluminium product = anode, lead = cathode. passing and electrical current through the electrolyte builds up a tough oxide layer.

Answer 10

Finely ground glass formed into a water based slurry, is sprayed onto metal components, eg. cooker components. it is then fired so the coating becomes a continuous layer of heat and scratch resistant material.

Answer 11

A method of applying paints to a product that has been statically charged. it is a dry process, which uses powder not paint. The powder is sprayed through an airgun that is positively charged, and the product is negatively charged, therefore there is a strong attraction between the two. Once coated the product is baked, melting the powder and producing a harder and tougher finish than paint. It is an environmentally sound method as no solvents are used and the excess can be recovered.

Answer 12

Involves shooting small spherical particles (like sand, or glass particles) at a surface to clean/prepare a surface (remove any residue from the surface). It’s used as a preparation process and can be used as a finishing process in its own right.

Answer 13

Advantages: • It can be used to make a controlled texture/Matt finish • Can be used to remove burrs and sharp edges of metal parts • Effective at removing contaminants from surfaces • It is relatively gentle compared to other methods • It is used to prepare metals • Can be used for restoring surfaces Disadvantages: • It can generate heat when high pressure or absrasive particles are used • Thin or lightweight parts may be damaged by the pressures • It can remove material from the surface (which may affect tolerances) • Can contaminate the surface • It is less practical for large and complex parts

Answer 14

A spray painting robotic arm will be programmed to cover all parts of the product with spray paint

Answer 15

Advantages: • Automated, meaning less chance of human error • Can be used in mass production • Little excess spray is used • Highly efficient and consistent Disadvantages: • High setup cost • Machines could break and cause disruption

Answer 16

It is a process where powder (made up of paint and resin particles). The particles that come out of the gun are given a charge, while the material that is being sprayed is grounded, meaning the particles are attracted to the material, meaning the product is fully covered and consistent.

Answer 17

Advantages: • It can be applied to any material • Strong, durable, corrosion resistant and cost efficient finish • Combination of chemical pigments • There are different levels of gloss and can be customised to give a unique finish • Resistant to chipping, scratching, and fading • Powder coating is time efficient and less costly • Doesn’t produce damaging pollutants and fumes • Generates less product waste Disadvantages: • Difficult to make thin even coatings (easy to make thick even coatings), this can affect tolerances • The materials used need to withstand curing temperature (need to be heat resistant) • Has a very high start up costs

Answer 18

Galvanising involves dipping parts in molten zinc to protect the steel underneath. The zinc bonds itself to the surface of the steel. This involves cathodic protection, where the zinc is sacrificed to protect the steel underneath

Answer 19

Advantages: • Extremely durable (can stay up to 100 years) • Has a low lifetime cost Disadvantages: • The material being galvanised needs to withstand the heat when being dipped • Is better used for large items

Answer 20

• Parts are disassembled • Stripping the metal removes particles which can affect the plate layer • Polishing refined and evens the surface in preparation for plating • The object is dipped into cleaning solution and electrified • The metal is then placed in the plate bath, where plating deposit begins. The longer an object is exposed to a current, the thicker the plating will become • Then post treatment takes place, in order to prevent tarnishing and improve resistance.

Answer 21

Advantages: • Gives a more consistent aesthetic finish • Coats inside the product effectively • Is a very thin layer applied, meaning tolerances will not be affected as much • Enhanced durability Disadvantages • It is a long process with many different stages • It is a complex and expensive process • Potential for defects

Answer 22

- The surface of the aluminium product needs cleaning prior to anodising. Exposing the surface uses acidic or alkaline cleaning agents to clean grease/dirt from the surface. - Pre-treatment eliminates any surface imperfections. The goal is to provide a visible finish with a clean and smooth surface. This is done by using two main processes – brightening and etching. Brightening cleans any heavy metal residues left over from the cleaning process. Etching removes a layer of aluminium from the product surface to provide a matte finish - After pre-treatment, the product is ready for anodising. As mentioned above, sulfuric acid is the go-to electrolyte for aluminium anodising. One method for colouring aluminium is electro colouring. In electrocolouring, the anodised aluminium product is introduced to inorganic metallic salts through an electrolyte. The anodised aluminium product becomes one electrolyte, and graphite (or aluminium) becomes the other. - Finally, sealing takes place and is the final step in the aluminium anodising process. This prevents water leakage and improves corrosion resistance to the anodised aluminium product

Answer 23

Cathodic protection is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell. A simple method of protection connects the metal to be protected to a more easily corroded "sacrificial metal" to act as the anode

Answer 24

Advantages: • Gives a very aesthetic finish • Easy to apply • Gives a shiny, glossy finish • Easy to clean Disadvantages: • Can be sharp when it chips • Enamel can become brittle

Metals Flashcards

(48 cards)