ผลการค้นหา

die casting mctal

แปลว่า(โลหะ) โลหะสีจางซึ่งเป็นโลหะผสมอาลูมิเนียม ตะกั่วสังกะสี หรือใช้โลหะทองแดงเป็น base มีส่วนผสมต่างกันหลายอย่าง ทั้งนี้ขึ้นอยู่กับการใช้ประเภทของงาน สำหรับโลหะหล่อใช้กับเครื่องยนต์นั้น ใช้โลหะผสมอาลูมิเนียม 90 % ทองแดง 4 % นิเกิ้ล 4 % และซิลิกอน 2% นิยมใช้แบบนี้กันมาก

Burning

แปลว่า(english) (1) Permanently damaging a metal or alloy by heating to cause either incipient melting or intergranular oxidation. (2) In grinding getting the work hot enough to cause discoloration or to change the microstructure by tempering or hardening.

Brinell Hardness

แปลว่า(english) The hardness of a metal or part, as represented by the number obtained from the ratio between the load applied on the spherical area of the impression made by a steel ball forced into the surface of the material tested.

Brasses

แปลว่า(english) Copper base alloys in which zinc is the principal alloying element. Brass is harder and mechanically stronger than either of its alloying elements copper or zinc. It is formable and ductile; develops high tensile strength with cold-working and is not heat treatable.

Hydrogenesis

แปลว่า(Concrete Engineering) Another term for condensation. The term is especially applied to base and soil substrates under highway pavements. where the barometric pump causes the inhalation of humid air, which then condenses in those structures, causing an ever increasing moisture content and sometimes instability.

Backwardation

แปลว่า(english) Market condition where the spot, or current price for a metal is higher than the three-month delivery price. This usually indicates immediate demand is perceived to be stronger than long-term demand. Not considered to be a "normal" market state (See Contango).

Brinell Hardness Number

แปลว่า(english) The value of hardness of a metal on an arbitrary scale representing kg/mm2, determined by measuring the diameter of the impression made by a ball of given diameter applied under a known load. Values are expressed in Brinell Hardness Numbers, BHN

Backer (back-up plate)

แปลว่า(english) A “tool” or reinforcing part, which presses against the outer surface of an extrusion die, supporting it against the pressure of the extruding metal. The backer has an opening larger than the die aperture, allowing the extruded product to emerge without marring its soft surface.

Bismuth

แปลว่า(english) Chemical symbol Bi. A soft, course cystalline heavy metal with a silvery white color and pinkish tinge; usually produced as a by-product of copper,leaad and other metals. Has a thermal conductivity lower than all other metals except mercury. Used as alloying agent but leading use is in pharmaceuticals.

Billet

แปลว่า(english) (1) A semi-finished section hot rolled from a metal ingot, with a rectangular cross section usually ranging from 16 to 36 in., the width being less than twice the thickness. Where the cross section exceeds 36 in., the term “bloom” is properly but not universally used. Sizes smaller than 16 in. are usually termed “bars”; a solid semi-finished round or square product which has been hot worked by forging, rolling, or extrusion. (2) A semi-finished, cogged, hot rolled or continuous-cast metal product of uniform section, usually rectangular with radiused corners. Billets are relatively larger than bars.

Boil

แปลว่า(english) Agitation of a bath of metal caused by the liberation of a gas beneath its surface. May be deliberately induced by the addition of oxidizing material to a bath containing excess carbon. In the later case it is called a carbon boil and CO or CO2 are liberated.

Basic Oxygen Furnace (BOF)

แปลว่า(english) "WHAT A pear-shaped furnace, lined with refractory bricks, that refines molten iron from the blast furnace and scrap into steel. Up to 30% of the charge into the BOF can be scrap, with hot metal accounting for the rest. WHY BOFs, which can refine a heat (batch) of steel in less than 45 minutes, replaced open-hearth furnaces in the 1950s; the latter required five to six hours to process the metal. The BOF's rapid operation, lower cost and ease of control give it a distinct advantage over previous methods. HOW Scrap is dumped into the furnace vessel, followed by the hot metal from the blast furnace. A lance is lowered from above, through which blows a high-pressure stream of oxygen to cause chemical reactions that separate impurities as fumes or slag. Once refined, the liquid steel and slag are poured into separate containers. "