Alloy refers to more than two kinds of metal elements or substances with metal characteristics composed of metal and non-metal. For example, steel and cast iron are alloys of iron and carbon
2015-05-26Using Brinell hardness measurement, because the residual indentation area is large, it can truly reflect the average hardness of the material, and the measurement data is stable. Therefore, it is used to measure materials with coarse or uneven tissue
2015-05-18After most metals crystallize, their lattice type will not change, but there are also a few metals, such as iron, cobalt and titanium, whose lattice type will change with the change of temperature in the solid state. This phenomenon is called
2015-05-23Among the more than 80 known metals, except for a few metals with complex crystal structure, most metals have relatively simple crystal structure, including body centered cubic lattice, face centered cubic lattice and closely arranged hexagonal lattice
2015-05-23Solid substances in nature are divided into crystalline and amorphous according to the characteristics of particle (atom or molecule) arrangement. A substance whose particles are periodically arranged in three-dimensional space according to a certain law is called a crystal; When the particles are scattered, they are called amorphous. In addition to a few substances in nature (such as paraffin, asphalt, ordinary glass, rosin, etc.), the vast majority
2015-05-23Rockwell hardness measurement uses diamond cone or quenched steel ball as indenter. Under the action of test force F, press the indenter into the material surface. After maintaining the specified time, remove the main test force, maintain the initial test force, and calculate the hardness value with the increment of residual indentation depth. During actual measurement, it can be directly measured through the dial of the testing machine
2015-05-19Graphite in cast iron and its influencing factors
2015-05-16Carbon in cast iron exists in the form of cementite or graphite.
2015-05-16Gravity casting: sand casting, hard mold casting. The molten metal is poured into the cavity by the gravity of the metal itself. Pressure casting: low pressure casting, high pressure casting. The molten metal is instantaneously pressed into the casting cavity by additional pressure.
2014-09-19Ordinary sand mold casting uses sand as mold material, also known as sand casting and sand turning, including wet sand mold, dry sand mold and chemical hardening sand mold, but not all sand can be used for casting. The advantage is lower cost, because the sand used in the mold can be reused; The disadvantage is that the manufacturing of the mold is time-consuming, and the mold itself cannot be reused. The finished product can be obtained only after it is destroyed.
2014-09-19
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