Unlock instant, AI-driven research and patent intelligence for your innovation.

Lead-free free-cutting graphite brass and preparation method thereof

A graphite brass and free-cutting technology, applied in the field of lead-free free-cutting graphite brass and its preparation, can solve the problems of large difference in specific gravity of graphite, uneven distribution of graphite particles and high porosity, and achieve good mechanical properties and cutting Machinability, excellent mechanical properties and machinability, the effect of simple production process

Active Publication Date: 2015-10-28
NANCHANG UNIV
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the main preparation methods of graphite brass are casting and powder metallurgy, but the size of graphite particles in the materials obtained by these two methods is relatively large
In addition, the specific gravity difference between graphite and copper is large, and graphite is easy to float during casting, resulting in uneven distribution of graphite particles; due to the poor wettability of graphite and copper substrates, the porosity of materials made by powder metallurgy is very low. High, especially with high graphite content
These factors will greatly reduce the machinability of graphite brass

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Lead-free free-cutting graphite brass and preparation method thereof
  • Lead-free free-cutting graphite brass and preparation method thereof
  • Lead-free free-cutting graphite brass and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Raw materials: 60wt% electrolytic copper, 5% gray cast iron, and zinc as the balance. First melt the copper and cast iron, then lower the temperature of the furnace and add zinc blocks, and after all the furnace materials are melted, they are taken out of the furnace and cast into rods. After removing the riser and surface defects of the copper rod, it was annealed at 900 °C for 10 h to obtain lead-free free-cutting graphite brass. The mass fraction of each component was: copper (Cu) 59~61wt%, iron (Fe) 4.5%, graphite ( C) 0.2%, silicon (Si) 0.1%, manganese (Mn) <0.03%, phosphorus (P) <0.01%, and the balance is zinc (Zn). The mechanical properties and cutting performance of the alloy are tested separately. In engineering, the cutting performance of HPb63-3 lead brass is usually taken as 100%, and other alloys are compared with it as the standard for evaluating the cutting performance of the alloy. The Vickers hardness of the component brass is 93HV, the tensile strengt...

Embodiment 2

[0024] Raw materials: 60wt% electrolytic copper, 10% gray cast iron, and zinc as the balance. First melt the copper and cast iron, then lower the temperature of the furnace and add zinc blocks, and after all the furnace materials are melted, they are taken out of the furnace and cast into rods. After removing the riser and surface defects of the copper rod, it was annealed at 900°C for 10 hours to obtain lead-free free-cutting graphite brass. The mass fraction of each component was: copper (Cu) 59~61wt%, iron (Fe) 9.2%, graphite ( C) 0.45%, silicon (Si) 0.21%, manganese (Mn) <0.05%, phosphorus (P) <0.03%, and the balance is zinc (Zn). The mechanical properties and cutting performance of the alloy are tested separately. In engineering, the cutting performance of HPb63-3 lead brass is usually taken as 100%, and other alloys are compared with it as the standard for evaluating the cutting performance of the alloy. The Vickers hardness of this component brass is 118HV, the tensile...

Embodiment 3

[0026] Raw materials: 60wt% electrolytic copper, 20% gray cast iron, and zinc as the balance. First melt the copper and cast iron, then lower the temperature of the furnace and add zinc blocks, and after all the furnace materials are melted, they are taken out of the furnace and cast into rods. After removing the riser and surface defects of the copper rod, it was annealed at 900°C for 10 hours to obtain lead-free free-cutting graphite brass. The mass fraction of each component was: copper (Cu) 59~61wt%, iron (Fe) 18%, graphite ( C) 1%, silicon (Si) 0.4%, manganese (Mn) <0.09%, phosphorus (P) <0.05%, and the balance is zinc (Zn). The mechanical properties and cutting performance of the alloy are tested separately. In engineering, the cutting performance of HPb63-3 lead brass is usually taken as 100%, and other alloys are compared with it as the standard for evaluating the cutting performance of the alloy. The Vickers hardness of this component brass is 145HV, the tensile stre...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
Vickers hardnessaaaaaaaaaa
tensile strengthaaaaaaaaaa
Login to View More

Abstract

The invention discloses lead-free free-cutting graphite brass and a preparation method thereof. The lead-free free-cutting graphite brass comprises the following components in percentage by weight: 57-61% of copper, 4.5-18.5% of iron, 0.2-0.5% of graphite, 0.1-0.3% of silicon, less than 0.08% of manganese, less than 0.03% of phosphorus and the balance of zinc. The preparation method comprises the following steps of: according to the proportion of 57-61wt% of electrolytic copper, 5-20wt% of cast iron and the balance of electrolytic zinc, firstly putting the electrolytic copper and the cast iron in an intermediate-frequency or power-frequency induction furnace, putting the cast iron at the bottom part of a crucible, using charcoal as a covering agent, reducing the temperature of the furnace after all the components are dissolved; adding the electrolytic zinc, mixing uniformly after all the materials in the furnace are dissolved, casting into bars, and carrying out graphitization annealing; and insulating heat for 8-15 hours at the temperature of 800-900 DEG C under the atmosphere of H2. The lead-free free-cutting graphite brass and the preparation method have the advantages that the problem of segregation of graphite when the graphite powder is directly used for casting the graphite brass is solved, and the defect of large porosity when a powder metallurgic method is adopted for preparing the graphite brass is avoided; graphite particles of a product are spherical, fine and scattered and the product has good mechanical performance and cutting processing performance, is friendly to the environment, has no harm to a human body; and the production process is simple and the cost is low.

Description

technical field [0001] The invention belongs to the field of alloy materials and preparation, in particular to a lead-free free-cutting graphite brass and a preparation method thereof. Background technique [0002] Leaded brass is a small amount of lead (about 1~4.5%) added to brass, which significantly improves the cutting performance of the material. Because of its low price, it is widely used in the manufacture of daily necessities and mechanical parts with complex shapes. However, lead is an element that is very harmful to the human body and the environment. Especially with the widespread application of lead brass in valves of civil water supply systems, the pollution and health problems caused by lead have become increasingly prominent. This has aroused the close attention of many developed countries. Economically developed countries such as the United States, Japan, and Europe have legislated to gradually ban the use of lead-containing copper alloys in drinking water ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C22C9/04C22C1/02C22F1/08
Inventor 唐建成卓海鸥薛莹妤叶楠
Owner NANCHANG UNIV