The difference between brass and bronze

Bronze is named for its blue color, and brass is named for its yellow color. So basically the color can be roughly distinguished. To be strictly distinguished, metallographic analysis is also required.

The dark green you mentioned is still the color of rust, not the true color of bronze.

The following introduces some basic knowledge of copper alloys:

copper alloy

Copper alloys are formed by adding certain alloying elements (such as zinc, tin, aluminum, beryllium, manganese, silicon, nickel, phosphorus, etc.) to pure copper. Copper alloys have good electrical conductivity, thermal conductivity and corrosion resistance, as well as high strength and wear resistance.

Depending on the composition, copper alloys are divided into brass and bronze.

1. Brass is a copper alloy with zinc as the main alloying element. According to the chemical composition, brass is divided into ordinary copper and special brass.

(1) Ordinary brass Ordinary brass is a copper-zinc binary alloy. Due to its good plasticity, it is suitable for the manufacture of plates, bars, wires, pipes and deep-drawing parts, such as condenser pipes, cooling pipes and mechanical and electrical parts. Brass with an average copper content of 62% and 59% can also be cast and is called cast brass.

(2) Special brass In order to obtain higher strength, corrosion resistance and good casting performance, aluminum, silicon, manganese, lead, tin and other elements are added to copper-zinc alloy to form special brass. Such as lead brass, tin brass, aluminum brass, silicon brass, manganese brass, etc.

Lead brass has excellent cutting performance and good wear resistance, and is widely used in the manufacture of watch parts, and is cast to make bearing bushes and bushings.

Tin brass has good corrosion resistance and is widely used in the manufacture of marine ship parts.

Aluminum in aluminum brass can improve the strength and hardness of brass and improve its corrosion resistance in the atmosphere. Aluminum brass is used to manufacture corrosion-resistant parts.

Silicon in silicon brass can improve the mechanical properties, wear resistance and corrosion resistance of copper. Silicon brass is mainly used to manufacture marine parts and chemical machinery parts.

bronze

Bronze originally refers to copper-tin alloy, but the industry is used to call copper alloys containing aluminum, silicon, lead, beryllium, manganese, etc. also bronze, so bronze actually includes tin bronze, aluminum bronze, aluminum bronze, beryllium bronze, silicon bronze , lead bronze, etc. Bronze is also divided into two categories: press-worked bronze and cast bronze.

(1) Tin bronze Copper-based alloy with tin as the main alloying element is called tin bronze. Most of the tin bronze used in industry has a tin content between 3% and 14%. Tin bronze with a tin content of less than 5% is suitable for cold working; tin bronze with a tin content of 5% to 7% is suitable for hot working; tin bronze with a tin content of more than 10% is suitable for casting. Tin bronze is widely used in shipbuilding, chemical industry, machinery, instrumentation and other industries. It is mainly used to manufacture wear-resistant parts such as bearings and bushings, elastic components such as springs, and anti-corrosion and anti-magnetic parts.

(2) Aluminum bronze Copper-based alloy with aluminum as the main alloying element is called aluminum bronze. The mechanical properties of aluminum bronze are higher than those of brass and tin bronze. The aluminum content of practical aluminum bronze is between 5% and 12%, and the aluminum bronze with aluminum content of 5% to 7% has the best plasticity and is suitable for cold working. When the aluminum content is greater than 7% to 8%, the strength increases, but the plasticity decreases sharply, so it is mostly used in the as-cast state or after hot working. The abrasion resistance and corrosion resistance of aluminum bronze in the atmosphere, seawater, seawater carbonic acid and most organic acids are higher than those of brass and tin bronze. Aluminum bronze can manufacture gears, bushings, worm gears and other high-strength wear-resistant parts and elastic components with high corrosion resistance.

(3) Beryllium bronze The copper alloy with beryllium as the basic element is called beryllium bronze. The beryllium content of beryllium bronze is 1.7% to 2.5%. Beryllium bronze has high elastic limit and fatigue limit, excellent wear resistance and corrosion resistance, good electrical conductivity and thermal conductivity, and also has the advantages of non-magnetic, no spark when impacted. Beryllium bronze is mainly used to make important springs for precision instruments, clock gears, bearings and bushings working under high speed and high pressure, as well as welding machine electrodes, explosion-proof tools, nautical compasses and other important parts.