阅读说明：本技术 一种高精度散热铝材的生产工艺 (Production process of high-precision heat dissipation aluminum material ) 是由 刘彦高 于 2021-07-21 设计创作，主要内容包括：本发明公开了一种高精度散热铝材的生产工艺,涉及铝材生产工艺技术领域,包括模具车间工艺、熔铸车间工艺、挤压车间工艺和喷涂车间工艺。本发明通过四大部分组成的完整的生产工艺,可实现铝材的加工,熔铸车间铸造过程中炉水化学成分、铝钛硼块添加量和铸造参数的精确设定,使得铝材能够达到预期的性能指标。(The invention discloses a production process of a high-precision heat-dissipation aluminum product, and relates to the technical field of aluminum product production processes. According to the invention, through a complete production process consisting of four major parts, the processing of the aluminum material can be realized, and the furnace water chemical composition, the addition amount of the aluminum-titanium-boron block and the casting parameters can be accurately set in the casting process of the casting workshop, so that the aluminum material can reach the expected performance index.)

1. The production process of the high-precision heat dissipation aluminum product comprises a die workshop process, a casting workshop process, an extrusion workshop process and a spraying workshop process, and is characterized in that:

the die workshop process comprises the following steps:

1) preparation before production: when the new furnace and the electric furnace are placed for more than one month for reuse, the furnace must be dried, and before the furnace is dried, the furnace filling and charging frame should be taken out; controlling the pressure output by the ammonia storage tank within 0.25 Mpa; the flow rate of ammonia gas is controlled at 2000-3000L/min;

2) cleaning a mold: the nitrogen chemical industry is to fill the serial numbers of the moulds needing to be fed into the furnace one by one on the record book of the nitrogen process; adding 36% hydrochloric acid and water at a ratio of 1:10 to obtain a water solution, soaking the mold in the water solution for ten minutes, and cleaning to remove dirt such as soil, oil stain and alkali on the surface of the mold; after being cleaned by hydrochloric acid, the mould is put into clean water for cleaning again; placing the mould into an alcohol solution for soaking for 10 minutes, and then cleaning;

3) and (3) drying: placing the mould cleaned by the alcohol in a well ventilated place for airing;

4) framing and furnace entering: after being dried, the moulds are placed in the material frame one by one in sequence, and enough space is reserved between the moulds; the charging amount of the die is controlled within a specified range, and the die cannot be overweight: the charging amount of the 60KW furnace is not more than 600 kg;

5) nitriding: before nitriding, ammonia gas is firstly introduced into the furnace (the exhaust time is 20-30 minutes), and the furnace can be heated to be not more than 150 ℃ at the same time, so that the nitriding temperature can be reached after the air in the furnace is less than 10%; observing the flow of ammonia gas at any time during the nitriding process, and performing decomposition once every thirty minutes; waste gas generated in the nitriding process is discharged by introducing water; after nitriding is finished, cutting off a power supply and starting a cooling fan; during the cooling process in the furnace, ammonia gas is continuously added and introduced into the tube;

6) discharging: when the temperature in the furnace is reduced to below 150 ℃ and the ammonia decomposition rate is reduced to 5%, the ammonia gas can be stopped being fed into the furnace and replaced by air, and the mold can be taken out;

the casting workshop process comprises the following steps:

1) preparing materials: raw aluminum ingots and unknown waste materials used for batching are required to be attached with chemical composition reports and can be used by a single party; the raw materials must have no water, no serious pollution and no adhesion of other metal alloys such as iron, copper and the like; the burden materials used must be accurately weighed and should be faithfully recorded on the record of the burden process; magnesium ingots for addition must be weighed using a small pound; during the calculation of the ingredients, the ratio of magnesium to silicon is ensured to be 1: 1.3-1.6, controlling the content of impurities not to exceed the standard, fully considering the burning loss of each element, weighing according to a batching list of a production department, and then blanking;

2) feeding: before feeding, cleaning a hearth to reach a preheating temperature of 700 ℃; uniformly loading small lump materials and foundry returns such as casting residual aluminum, rod heads and rod tails, extrusion residual, small parts of extrusion head tails and the like on a furnace bottom, and then feeding aluminum ingots and aluminum-silicon intermediate alloys;

3) smelting: the temperature of the smelting furnace is less than or equal to 1000 ℃, and the temperature of the aluminum liquid is 720 ℃ and 760 ℃; after the surface metal is melted, pushing the aluminum ingot which is not melted to a high-temperature area for accelerating melting, and uniformly stirring;

4) primary refining and slagging-off: the refining temperature is 710-750 ℃, the dosage of the refining agent is 4kg-6kg/T, the refining time is 20-30 minutes, the dosage of the slag removing agent is 4kg-6kg/T, and the nitrogen pressure is 10 MPa; the refining pipe is inserted into the lower part of the molten aluminum, is about 100mm away from the furnace bottom, reciprocates back and forth and left and right, stably and slowly moves, and circulates from outside to inside without dead angles;

5) adding magnesium: when adding magnesium ingot, the temperature of the melt is less than or equal to 730 ℃, and when adding magnesium ingot, the magnesium ingot is quickly pressed into the melt by using a bell jar;

6) secondary refining and sampling: the refining time is 20-30min, the refining temperature is 710-750 ℃, the dosage of the refining agent is 4-6kg/T, the nitrogen pressure is 10MPa, and the dosage of the nitrogen is 1.5 bottles; thoroughly stirring the melt to make the components uniform, and selecting 5 points in four corners and the center below the liquid level of 150mm in the furnace, wherein each point is not less than 100 g, and taking a furnace front analysis sample;

7) standing: standing for 20-30min, completely removing floating slag after refining;

8) casting: the chemical components of the furnace water, the addition amount of the aluminum-titanium-boron block and the casting parameters are respectively shown in tables 1, 2 and 3:

table 1, furnace water chemistry:

silicon Magnesium alloy Iron Copper (Cu) Manganese oxide Zinc 0.38～0.45 0.55～0.72 ≤0.3 ≤0.1 ≤0.1 ≤0.1

Table 2, addition amount of aluminum titanium boron block:

table 3, casting parameters:

the casting cooling water must be filtered by a 0.5mm filter screen;

9) sawing: the appearance quality requirements and the geometric dimensions of the sawing bars are shown in tables 4 and 5:

table 4, requirements of the saw cutting bar for appearance quality:

length of Slope of end face Degree of curvature Diameter of metal tumor Depth of pull mark Width of pull mark -1～3mm ±2° ＜0.35mm/m ＜3mm ＜3mm ＜2mm

Table 5, geometry:

control item Process requirements Tolerance of length 0＜L＜5mm Degree of tangential slope 0＜r≤5mm

10) Framing: sequentially framing, and marking the net weight, the count, the length and the diameter of the aluminum rod of each frame by chalk on a material frame;

the extrusion workshop process comprises the following steps:

1) heating a mould: the parameters are shown in Table 6:

table 6, mold heating parameters:

2) heating an aluminum bar: the parameters are shown in Table 7:

table 7, aluminum bar heating parameters:

3) heating a material container: controlling the heating temperature of the ingot container (the internal temperature measured in the material container by a temperature measurer) to 380-430 ℃, wherein the external temperature generally reaches 280-360 ℃;

4) extruding: before extrusion, the central position of a die frame, the central position of a material container and the central position of a machine rod balance (commonly called three centers) are required to be adjusted on the same central line, so that the three centers are ensured to be consistent; the extrusion pressure, speed and temperature parameters are shown in table 8:

table 8, extrusion pressure, speed and temperature parameters:

5) and (3) cooling: the temperature is reduced by 50-60 ℃ per second when the collar is required to be rapidly tightened; when the discharge length is 12m, the temperature of the stub bar is controlled below 220 ℃, and when the discharge length reaches 18m, the temperature of the stub bar is controlled below 170 ℃;

6) stretching and straightening: the stretching rate is controlled to be 0.5-2%, and the stretching temperature is controlled to be below 60 ℃;

7) sawing: the parameters are shown in Table 9:

TABLE 9 saw cutting parameters

8) Framing: placing the sawed product into an iron frame, and carrying the product lightly without collision and neatly placing the product;

9) aging: controlling the temperature of the aging furnace at 200 +/-10 ℃ and keeping the temperature for 2-3 h, and then discharging the furnace; naturally cooling the discharged product for 30min, and measuring the hardness with hardness pliers until the hardness is more than or equal to 8 hw;

the spraying workshop process comprises the following steps: 1) detecting the surface quality; 2) polishing; 3) blowing; 4) degreasing; 5) washing with water; 6) pure water washing; 7) dripping to dry; 8) drying; 9) powder spraying; 10) curing; 11) detecting; 12) and (6) packaging.

2. A production process of a high-precision heat dissipation aluminum material as recited in claim 1, characterized in that: the parameters of the degreasing tank of the degreasing process in the spray workshop process are shown in the table 10:

table 10, degreasing bath parameters:

。

3. a production process of a high-precision heat dissipation aluminum material as recited in claim 1, characterized in that: the parameters of the powder spraying process in the spray shop process are shown in table 11:

table 11, powder spray parameters:

chain speed (m/min) Electrostatic voltage (kv) Air pressure (bar) Current (Ua) 2-4 40-80 4-6（30％-60％） 8-30

。

4. A production process of a high-precision heat dissipation aluminum material as recited in claim 1, characterized in that: the curing conditions in the spraying workshop process are as follows: the surface temperature is 185-230 ℃ and the time is 15-20 minutes (determined according to the chain speed and the coating performance).

5. A production process of a high-precision heat dissipation aluminum material as recited in claim 1, characterized in that: the packaging process in the spraying workshop process comprises the following steps: selecting a proper protective film according to the decorative surface during film pasting, wherein the protective film is required to be completely attached to the section bar, and the speed of a film pasting machine is generally controlled to be 3-6 m/s; the temperature of the shrink film sleeving product must be controlled at 200-300 ℃ when the shrink film sleeving product is in the machine state, so that the appearance effect of the shrunk product is guaranteed.

Technical Field

The invention relates to the technical field of aluminum product production processes, in particular to a production process of a high-precision heat dissipation aluminum product.

Background

Aluminum alloy sections are the most widely used non-ferrous metal structural materials in industry. The pure aluminum has small density which is about 1/3 of iron and low melting point, and the aluminum has a face-centered cubic structure, so the pure aluminum has high plasticity and is easy to process and can be made into various sectional materials and plates; however, pure aluminum has a very low strength and is not suitable as a structural material. Through long-term production practices and scientific experiments, people gradually add alloy elements and apply heat treatment and other methods to strengthen aluminum, so that a series of aluminum alloys are obtained. The alloy formed by adding certain elements has higher strength while keeping the advantages of light weight of pure aluminum and the like, so that the specific strength of the alloy is superior to that of a plurality of alloy steels, and the alloy becomes an ideal structural material. Therefore, the aluminum alloy has the characteristics of low density and high strength, is close to or superior to high-quality steel, has good plasticity, can be processed into various sections, has excellent electrical conductivity, thermal conductivity and corrosion resistance, is widely used in industry, and is second to steel in use amount. Aluminum alloy sections will become the mainstream of the market in the next few years.

At the present stage, along with diversification of use scenes, the performance requirements of the aluminum material are higher and higher, and a production process of a high-precision heat dissipation aluminum material is needed to enable the aluminum material to meet the relevant performance requirements.

Disclosure of Invention

The invention aims to provide a production process of a high-precision heat dissipation aluminum material, which aims to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a production process of a high-precision heat-dissipation aluminum material comprises a die workshop process, a casting workshop process, an extrusion workshop process and a spraying workshop process,

the die workshop process comprises the following steps:

1) preparation before production: when the new furnace and the electric furnace are placed for more than one month for reuse, the furnace must be dried, and before the furnace is dried, the furnace filling and charging frame should be taken out; controlling the pressure output by the ammonia storage tank within 0.25 Mpa; the flow rate of ammonia gas is controlled at 2000-3000L/min;

2) cleaning a mold: the nitrogen chemical industry is to fill the serial numbers of the moulds needing to be fed into the furnace one by one on the record book of the nitrogen process; adding 36% hydrochloric acid and water at a ratio of 1:10 to obtain a water solution, soaking the mold in the water solution for ten minutes, and cleaning to remove dirt such as soil, oil stain and alkali on the surface of the mold; after being cleaned by hydrochloric acid, the mould is put into clean water for cleaning again; placing the mould into an alcohol solution for soaking for 10 minutes, and then cleaning;

3) and (3) drying: placing the mould cleaned by the alcohol in a well ventilated place for airing;

4) framing and furnace entering: after being dried, the moulds are placed in the material frame one by one in sequence, and sufficient space is reserved between the moulds to ensure that gas in the furnace is smooth up and down; the charging amount of the die is controlled within a specified range, and the die cannot be overweight: the charging amount of the 60KW furnace is not more than 600 kg;

5) nitriding: before nitriding, ammonia gas is firstly introduced into the furnace to drive out air in the furnace (the exhaust time is 20-30 minutes), and the furnace can be heated to be not more than 150 ℃ to prevent the workpiece from being oxidized, so that the nitriding temperature can be reached after the air in the furnace is less than 10%; observing the flow of ammonia gas at any time during the nitriding process, and performing decomposition once every thirty minutes; waste gas generated in the nitriding process is discharged by introducing water; after nitriding is finished, cutting off a power supply and starting a cooling fan; during the cooling process in the furnace, ammonia gas is continuously added into the tube, so that the positive pressure in the furnace is maintained, air is prevented from permeating into the furnace, and the decomposition rate of the ammonia gas in the furnace can be reduced;

6) discharging: when the temperature in the furnace is reduced to below 150 ℃ and the ammonia decomposition rate is reduced to 5%, the ammonia gas is stopped being fed into the furnace and replaced by air, and the die can be taken out, otherwise, the workpiece is discolored, the nitriding quality is reduced, and even sometimes, the workpiece can explode.

The casting workshop process comprises the following steps:

1) preparing materials: raw aluminum ingots and unknown waste materials used for batching are required to be attached with chemical composition reports and can be used by a single party; the raw materials must have no water, no serious pollution and no adhesion of other metal alloys such as iron, copper and the like; the burden materials used must be accurately weighed and should be faithfully recorded on the record of the burden process; magnesium ingots for addition must be weighed using a small pound; during the calculation of the ingredients, the ratio of magnesium to silicon is ensured to be 1: 1.3-1.6, controlling the content of impurities not to exceed the standard, fully considering the burning loss of each element, weighing according to a batching list of a production department, and then blanking;

2) feeding: before feeding, cleaning a hearth to reach a preheating temperature of 700 ℃; uniformly loading small lump materials and foundry returns such as casting residual aluminum, rod heads and rod tails, extrusion residual, a small part of extrusion head tails and the like on the furnace bottom, and then feeding aluminum ingots and aluminum-silicon intermediate alloys to protect the furnace bottom of a smelting furnace;

3) smelting: the temperature of the smelting furnace is less than or equal to 1000 ℃, and the temperature of the aluminum liquid is 720 ℃ and 760 ℃; after the surface metal is melted, pushing the aluminum ingot which is not melted to a high-temperature area to accelerate melting, and uniformly stirring to prevent local overheating;

4) primary refining and slagging-off: the refining temperature is 710-750 ℃, the dosage of the refining agent is 4kg-6kg/T, the refining time is 20-30 minutes, the dosage of the slag removing agent is 4kg-6kg/T, and the nitrogen pressure is 10 MPa; the refining pipe is inserted into the lower part of the molten aluminum, is about 100mm away from the furnace bottom, reciprocates back and forth and left and right, stably and slowly moves, and circulates from outside to inside without dead angles;

5) adding magnesium: when adding magnesium ingot, the temperature of the melt is less than or equal to 730 ℃, and when adding magnesium ingot, the magnesium ingot is quickly pressed into the melt by a bell jar to reduce burning loss;

6) secondary refining and sampling: the refining time is 20-30min, the refining temperature is 710-750 ℃, the dosage of the refining agent is 4-6kg/T, the nitrogen pressure is 10MPa, and the dosage of the nitrogen is 1.5 bottles; thoroughly stirring the melt to make the components uniform, selecting 5 points from four corners and the center below the liquid level of 150mm in the furnace, and taking a furnace front analysis sample with each point not less than 100 g so as to adjust the melt according to an analysis result;

7) standing: standing for 20-30min, completely removing floating slag after refining;

8) casting: the chemical components of the furnace water, the addition amount of the aluminum-titanium-boron block and the casting parameters are respectively shown in tables 1, 2 and 3:

table 1, furnace water chemistry:

silicon	Magnesium alloy	Iron	Copper (Cu)	Manganese oxide	Zinc
						0.38～0.45	0.55～0.72	≤0.3	≤0.1	≤0.1	≤0.1

Table 2, addition amount of aluminum titanium boron block:

table 3, casting parameters:

the casting cooling water must be filtered by a 0.5mm filter screen;

9) sawing: the appearance quality requirements and the geometric dimensions of the sawing bars are shown in tables 4 and 5:

table 4, requirements of the saw cutting bar for appearance quality:

length of	Slope of end face	Degree of curvature	Diameter of metal tumor	Depth of pull mark	Width of pull mark
						-1～3mm	±2°	＜0.35mm/m	＜3mm	＜3mm	＜2mm

Table 5, geometry:

control item	Process requirements
		Tolerance of length	0＜L＜5mm
Degree of tangential slope	0＜r≤5mm

10) Framing: sequentially framing, and marking the net weight, the count, the length and the diameter of the aluminum rod of each frame by chalk on a material frame;

the extrusion workshop process comprises the following steps:

1) heating a mould: the parameters are shown in Table 6:

table 6, mold heating parameters:

2) heating an aluminum bar: the parameters are shown in Table 7:

table 7, aluminum bar heating parameters:

3) heating a material container: controlling the heating temperature of the ingot container (the internal temperature measured in the material container by a temperature measurer) to 380-430 ℃, wherein the external temperature generally reaches 280-360 ℃;

4) extruding: before extrusion, the central position of a die frame, the central position of a material container and the central position of a machine rod balance (commonly called three centers) are required to be adjusted on the same central line, so that the three centers are ensured to be consistent; the extrusion pressure, speed and temperature parameters are shown in table 8:

table 8, extrusion pressure, speed and temperature parameters:

5) and (3) cooling: the temperature is reduced by 50-60 ℃ per second when the collar is required to be rapidly tightened; when the discharge length is 12m, the temperature of the stub bar is controlled below 220 ℃, and when the discharge length reaches 18m, the temperature of the stub bar is controlled below 170 ℃;

6) stretching and straightening: the stretching rate is controlled to be 0.5-2%, and the stretching temperature is controlled to be below 60 ℃;

7) sawing: the parameters are shown in Table 9:

TABLE 9 saw cutting parameters

8) Framing: placing the sawed product into an iron frame, and carrying the product lightly without collision and neatly placing the product;

9) aging: controlling the temperature of the aging furnace at 200 +/-10 ℃ and keeping the temperature for 2-3 h, and then discharging the furnace; naturally cooling the discharged product for 30min, and measuring the hardness with hardness pliers until the hardness is more than or equal to 8 hw;

the spraying workshop process comprises the following steps: 1) detecting the surface quality; 2) polishing; 3) blowing; 4) degreasing; 5) washing with water; 6) pure water washing; 7) dripping to dry; 8) drying; 9) powder spraying; 10) curing; 11) detecting; 12) and (6) packaging.

Preferably, the parameters of the degreasing tank of the degreasing process in the spray shop process are shown in table 10:

table 10, degreasing bath parameters:

preferably, the parameters of the powder spraying process in the spray shop process are shown in table 11:

table 11, powder spray parameters:

chain speed (m/min)	Electrostatic voltage (kv)	Air pressure (bar)	Current (Ua)
				2-4	40-80	4-6（30％-60％）	8-30

Preferably, the curing conditions in the spray shop process are as follows: the surface temperature is 185-230 ℃ and the time is 15-20 minutes (determined according to the chain speed and the coating performance).

Preferably, the packaging process in the spray workshop process is as follows: selecting a proper protective film according to the decorative surface during film pasting, wherein the protective film is required to be completely attached to the section bar, and the speed of a film pasting machine is generally controlled to be 3-6 m/s; the temperature of the shrink film sleeving product must be controlled at 200-300 ℃ when the shrink film sleeving product is in the machine state, so that the appearance effect of the shrunk product is guaranteed.

Compared with the prior art, the invention has the beneficial effects that: the aluminum product can be processed by a complete production process consisting of four major parts, namely a die workshop process, a casting workshop process, an extrusion workshop process and a spraying workshop process, and the furnace water chemical composition, the addition amount of aluminum-titanium-boron blocks and casting parameters are accurately set in the casting process of the casting workshop, so that the aluminum product can reach the expected performance index.

Drawings

FIG. 1 is a general flow diagram of the process of the present invention;

FIG. 2 is a process flow diagram of a mold shop of the present invention;

FIG. 3 is a process flow diagram of a fusion casting plant of the present invention;

FIG. 4 is a flow chart of the extrusion shop process of the present invention;

FIG. 5 is a flow chart of the spray shop process of the present invention; .

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-5, the present invention provides a technical solution: a production process of a high-precision heat-dissipation aluminum material comprises a die workshop process, a casting workshop process, an extrusion workshop process and a spraying workshop process,

the die workshop process comprises the following steps:

1) preparation before production: when the new furnace and the electric furnace are placed for more than one month for reuse, the furnace must be dried, and before the furnace is dried, the furnace filling and charging frame should be taken out; controlling the pressure output by the ammonia storage tank within 0.25 Mpa; the flow rate of ammonia gas is controlled at 2000-3000L/min;

2) cleaning a mold: the nitrogen chemical industry is to fill the serial numbers of the moulds needing to be fed into the furnace one by one on the record book of the nitrogen process; adding 36% hydrochloric acid and water at a ratio of 1:10 to obtain a water solution, soaking the mold in the water solution for ten minutes, and cleaning to remove dirt such as soil, oil stain and alkali on the surface of the mold; after being cleaned by hydrochloric acid, the mould is put into clean water for cleaning again; placing the mould into an alcohol solution for soaking for 10 minutes, and then cleaning;

3) and (3) drying: placing the mould cleaned by the alcohol in a well ventilated place for airing;

4) framing and furnace entering: after being dried, the moulds are placed in the material frame one by one in sequence, and sufficient space is reserved between the moulds to ensure that gas in the furnace is smooth up and down; the charging amount of the die is controlled within a specified range, and the die cannot be overweight: the charging amount of the 60KW furnace is not more than 600 kg;

5) nitriding: before nitriding, ammonia gas is firstly introduced into the furnace to drive out air in the furnace (the exhaust time is 20-30 minutes), and the furnace can be heated to be not more than 150 ℃ to prevent the workpiece from being oxidized, so that the nitriding temperature can be reached after the air in the furnace is less than 10%; observing the flow of ammonia gas at any time during the nitriding process, and performing decomposition once every thirty minutes; waste gas generated in the nitriding process is discharged by introducing water; after nitriding is finished, cutting off a power supply and starting a cooling fan; during the cooling process in the furnace, ammonia gas is continuously added into the tube, so that the positive pressure in the furnace is maintained, air is prevented from permeating into the furnace, and the decomposition rate of the ammonia gas in the furnace can be reduced;

6) discharging: when the temperature in the furnace is reduced to below 150 ℃ and the ammonia decomposition rate is reduced to 5%, the ammonia gas is stopped being fed into the furnace and replaced by air, and the die can be taken out, otherwise, the workpiece is discolored, the nitriding quality is reduced, and even sometimes, the workpiece can explode.

The casting workshop process comprises the following steps:

1) preparing materials: raw aluminum ingots and unknown waste materials used for batching are required to be attached with chemical composition reports and can be used by a single party; the raw materials must have no water, no serious pollution and no adhesion of other metal alloys such as iron, copper and the like; the burden materials used must be accurately weighed and should be faithfully recorded on the record of the burden process; magnesium ingots for addition must be weighed using a small pound; during the calculation of the ingredients, the ratio of magnesium to silicon is ensured to be 1: 1.3-1.6, and controlling the impurity content not to exceed the standard, and fully considering the burning loss of each element. Weighing the materials according to the batching list of the production part and then discharging;

2) feeding: before feeding, cleaning a hearth to reach a preheating temperature of 700 ℃; uniformly loading small lump materials and foundry returns such as casting residual aluminum, rod heads and rod tails, extrusion residual, a small part of extrusion head tails and the like on the furnace bottom, and then feeding aluminum ingots and aluminum-silicon intermediate alloys to protect the furnace bottom of a smelting furnace;

3) smelting: the temperature of the smelting furnace is less than or equal to 1000 ℃, and the temperature of the aluminum liquid is 720 ℃ and 760 ℃; after the surface metal is melted, pushing the aluminum ingot which is not melted to a high-temperature area to accelerate melting, and uniformly stirring to prevent local overheating;

4) primary refining and slagging-off: the refining temperature is 710-750 ℃, the dosage of the refining agent is 4kg-6kg/T, the refining time is 20-30 minutes, the dosage of the slag removing agent is 4kg-6kg/T, and the nitrogen pressure is 10 MPa; the refining pipe is inserted into the lower part of the molten aluminum, is about 100mm away from the furnace bottom, reciprocates back and forth and left and right, stably and slowly moves, and circulates from outside to inside without dead angles;

5) adding magnesium: when adding magnesium ingot, the temperature of the melt is less than or equal to 730 ℃, and when adding magnesium ingot, the magnesium ingot is quickly pressed into the melt by a bell jar to reduce burning loss;

6) secondary refining and sampling: the refining time is 20-30min, the refining temperature is 710-750 ℃, the dosage of the refining agent is 4-6kg/T, the nitrogen pressure is 10MPa, and the dosage of the nitrogen is 1.5 bottles; thoroughly stirring the melt to make the components uniform, selecting 5 points from four corners and the center below the liquid level of 150mm in the furnace, and taking a furnace front analysis sample with each point not less than 100 g so as to adjust the melt according to an analysis result;

7) standing: standing for 20-30min, completely removing floating slag after refining;

8) casting: the chemical components of the furnace water, the addition amount of the aluminum-titanium-boron block and the casting parameters are respectively shown in tables 1, 2 and 3:

table 1, furnace water chemistry:

silicon	Magnesium alloy	Iron	Copper (Cu)	Manganese oxide	Zinc
						0.38～0.45	0.55～0.72	≤0.3	≤0.1	≤0.1	≤0.1

Table 2, addition amount of aluminum titanium boron block:

table 3, casting parameters:

the casting cooling water must be filtered by a 0.5mm filter screen;

9) sawing: the appearance quality requirements and the geometric dimensions of the sawing bars are shown in tables 4 and 5:

table 4, requirements of the saw cutting bar for appearance quality:

length of	Slope of end face	Degree of curvature	Diameter of metal tumor	Depth of pull mark	Width of pull mark
						-1～3mm	±2°	＜0.35mm/m	＜3mm	＜3mm	＜2mm

Table 5, geometry:

control item	Process requirements
		Tolerance of length	0＜L＜5mm
Degree of tangential slope	0＜r≤5mm

10) Framing: sequentially framing, and marking the net weight, the count, the length and the diameter of the aluminum rod of each frame by chalk on a material frame;

the extrusion workshop process comprises the following steps:

1) heating a mould: the parameters are shown in Table 6:

table 6, mold heating parameters:

2) heating an aluminum bar: the parameters are shown in Table 7:

table 7, aluminum bar heating parameters:

3) heating a material container: controlling the heating temperature of the ingot container (the internal temperature measured in the material container by a temperature measurer) to 380-430 ℃, wherein the external temperature generally reaches 280-360 ℃;

4) extruding: before extrusion, the central position of a die frame, the central position of a material container and the central position of a machine rod balance (commonly called three centers) are required to be adjusted on the same central line, so that the three centers are ensured to be consistent; the extrusion pressure, speed and temperature parameters are shown in table 8:

table 8, extrusion pressure, speed and temperature parameters:

5) and (3) cooling: the temperature is reduced by 50-60 ℃ per second when the collar is required to be rapidly tightened; when the discharge length is 12m, the temperature of the stub bar is controlled below 220 ℃, and when the discharge length reaches 18m, the temperature of the stub bar is controlled below 170 ℃;

6) stretching and straightening: the stretching rate is controlled to be 0.5-2%, and the stretching temperature is controlled to be below 60 ℃;

7) sawing: the parameters are shown in Table 9:

TABLE 9 saw cutting parameters

8) Framing: placing the sawed product into an iron frame, and carrying the product lightly without collision and neatly placing the product;

9) aging: controlling the temperature of the aging furnace at 200 +/-10 ℃ and keeping the temperature for 2-3 h, and then discharging the furnace; naturally cooling the discharged product for 30min, and measuring the hardness with hardness pliers until the hardness is more than or equal to 8 hw;

the spraying workshop process comprises the following steps: 1) detecting the surface quality; 2) polishing; 3) blowing; 4) degreasing; 5) washing with water; 6) pure water washing; 7) dripping to dry; 8) drying; 9) powder spraying; 10) curing; 11) detecting; 12) and (6) packaging.

The degreasing bath parameters of the degreasing process in the spray shop process are shown in table 10:

table 10, degreasing bath parameters:

the parameters of the powder spraying process in the spray shop process are shown in table 11:

table 11, powder spray parameters:

chain speed (m/min)	Electrostatic voltage (kv)	Air pressure (bar)	Current (Ua)
				2-4	40-80	4-6（30％-60％）	8-30

The curing conditions in the spraying workshop process are as follows: the surface temperature is 185-230 ℃ and the time is 15-20 minutes (determined according to the chain speed and the coating performance).

The packaging process in the spraying workshop process comprises the following steps: selecting a proper protective film according to the decorative surface during film pasting, wherein the protective film is required to be completely attached to the section bar, and the speed of a film pasting machine is generally controlled to be 3-6 m/s; the temperature of the shrink film sleeving product must be controlled at 200-300 ℃ when the shrink film sleeving product is in the machine state, so that the appearance effect of the shrunk product is guaranteed.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.