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Powder metallurgy machine parts - parts
2020-03-24
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返回列表Manufactured by powder metallurgy method of mechanical parts, also known as sintered mechanical parts. Usually includes mechanical parts, oil-bearing and friction parts; narrowly refers to the structural components. Initially there is a sintered mechanical parts sintered metal oil bearing. 1910 Swede 勒夫恩达尔 (VL wendal) made modern manufacturing sintered bronze oil-bearing patent. Later, the Americans Gilson (EGGilson) to achieve such a bearing of industrial production. 1930 formally established the status of its industrial products. In 1933, Germany began to develop sintered iron-based Bearings. The late 1930s the United States has a large number of production and use of sintered iron-based oil pump gear to replace the cast iron products. Since the 1960s, due to improvements in the quality iron and powder development of new varieties, forming technology, equipment, forming equipment and the development of sintering, sintering machine parts to improve the performance of the growing, increasingly complex shapes, production is increasing rapidly. Sintered industrial countries over the past decade the average annual increase of mechanical parts rate of about 10 to 15%. China began production in 1954 Oil-bearing copper, iron-based oil production in 1957, bearing, to 70 years, sintered parts in production machinery has been well established in the agricultural machinery, automobiles, machine tools, instruments, textiles, light industry has been more widely used.
Material sintered materials and the general casting and forging machinery parts materials, the main difference is that the former is a controllable variable density; in both chemical composition and microstructure similar conditions, the mechanical properties of the former is a function of its density. Affect its mechanical properties is another important factor is the alloying elements. In the iron-based sintered material is the most widely used alloying elements carbon, copper, nickel, molybdenum. Carbon can be used alone or in conjunction with other elements (particularly copper) used mainly for improving the iron-based sintered material strength and hardness; copper, nickel, molybdenum is a common feature of affinity with oxygen than iron is small, it contains these elements alloy powder body, the general sintering in an atmosphere of pure iron sintering.
In the production of sintered iron-based materials, copper is the most widely used alloying elements. And he was melting in the sintering of copper, and dissolved iron, alloyed with iron, thus greatly improving the strength of sintered iron-based materials. Such as copper or nickel as both carbon and alloy elements, sintered iron-based materials mechanical properties can be further improved. In the sintered iron-based materials is mainly molybdenum added to increase hardenability. Mo sintered materials on the mechanical properties of sintered state has a good role. Thus, gradually formed a sintered iron, sintered steel, sintered copper steel, sintered molybdenum steel, sintered nickel-molybdenum alloy steel and sintered stainless steel series. In the 1970s by adding iron to phosphorus in iron, phosphorus and carbon to form a sintered iron alloy. Non-ferrous alloys in sintering, the development of sintered bronze, sintered brass, sintered aluminum alloy.
Material density, pore size, shape and distribution, and degree of sintering sintering the mechanical properties of materials, mechanical parts have a significant impact (see powder metallurgy sintering). Based on material density, tensile strength of sintered carbon steel 11 ~ 42kgf/mm2, heat treatment can be increased to 63kgf/mm2 more. Tensile strength of sintered copper steel 14 ~ 57kgf/mm2, after heat treatment up to 70kgf/mm2 more. The tensile strength of sintered brass 28kgf/mm2. The tensile strength of sintered aluminum alloy is generally 10 ~ 35kgf/mm2. Sintered material due to the presence of residual porosity (typically 5 to 25%), the ductility and toughness are low. Although the adoption of re-pressure, re-burn, melt infiltration, subsequent heat treatment, changes in the morphology and number of pores, can improve its mechanical properties, in particular, fatigue strength, impact toughness and ductility, but still can not reach the performance of the corresponding casting and forging material level, so the application of sintered mechanical parts is limited. However, production of machine parts with sintering method, with the use of casting, forging, machining methods of production parts, compared with the energy savings, fewer manufacturing processes, materials utilization, and high dimensional accuracy, uniform, suitable for high-volume automated production, etc. range of applications has also been expanded.
Material sintered materials and the general casting and forging machinery parts materials, the main difference is that the former is a controllable variable density; in both chemical composition and microstructure similar conditions, the mechanical properties of the former is a function of its density. Affect its mechanical properties is another important factor is the alloying elements. In the iron-based sintered material is the most widely used alloying elements carbon, copper, nickel, molybdenum. Carbon can be used alone or in conjunction with other elements (particularly copper) used mainly for improving the iron-based sintered material strength and hardness; copper, nickel, molybdenum is a common feature of affinity with oxygen than iron is small, it contains these elements alloy powder body, the general sintering in an atmosphere of pure iron sintering.
In the production of sintered iron-based materials, copper is the most widely used alloying elements. And he was melting in the sintering of copper, and dissolved iron, alloyed with iron, thus greatly improving the strength of sintered iron-based materials. Such as copper or nickel as both carbon and alloy elements, sintered iron-based materials mechanical properties can be further improved. In the sintered iron-based materials is mainly molybdenum added to increase hardenability. Mo sintered materials on the mechanical properties of sintered state has a good role. Thus, gradually formed a sintered iron, sintered steel, sintered copper steel, sintered molybdenum steel, sintered nickel-molybdenum alloy steel and sintered stainless steel series. In the 1970s by adding iron to phosphorus in iron, phosphorus and carbon to form a sintered iron alloy. Non-ferrous alloys in sintering, the development of sintered bronze, sintered brass, sintered aluminum alloy.
Material density, pore size, shape and distribution, and degree of sintering sintering the mechanical properties of materials, mechanical parts have a significant impact (see powder metallurgy sintering). Based on material density, tensile strength of sintered carbon steel 11 ~ 42kgf/mm2, heat treatment can be increased to 63kgf/mm2 more. Tensile strength of sintered copper steel 14 ~ 57kgf/mm2, after heat treatment up to 70kgf/mm2 more. The tensile strength of sintered brass 28kgf/mm2. The tensile strength of sintered aluminum alloy is generally 10 ~ 35kgf/mm2. Sintered material due to the presence of residual porosity (typically 5 to 25%), the ductility and toughness are low. Although the adoption of re-pressure, re-burn, melt infiltration, subsequent heat treatment, changes in the morphology and number of pores, can improve its mechanical properties, in particular, fatigue strength, impact toughness and ductility, but still can not reach the performance of the corresponding casting and forging material level, so the application of sintered mechanical parts is limited. However, production of machine parts with sintering method, with the use of casting, forging, machining methods of production parts, compared with the energy savings, fewer manufacturing processes, materials utilization, and high dimensional accuracy, uniform, suitable for high-volume automated production, etc. range of applications has also been expanded.
