JP2016101592A - Method for welding aluminum-based member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding method for an aluminum-based member capable of securing a large weld penetration depth, reducing the number of blow holes and stably carrying out a high-quality welding in an electron beam welding or the like.SOLUTION: A welding method for an aluminum-based member has a welding process of welding to each other processing part, a couple of aluminum-based members comprising aluminum or aluminum alloy and having the processing part machined using a water-soluble processing oil. The method is characterized by comprising a cleaning process of cleaning at least the processing part to be welded using an alkaline electrolytic ion water obtained by electrolysis of water and a drying process of drying the cleaned processing part prior to the welding process. Preferably, the electrolytic ion water is a warm water of pH 8 to 11, and the aluminum-based member includes Si (silicon).SELECTED DRAWING: Figure 2

Description

  The present invention relates to an aluminum-based member welding method capable of stably providing a high-quality aluminum-based member by reducing defective welding.

  A structural member having a complicated shape is often manufactured by welding a plurality of members at predetermined positions. In the case of a member requiring high accuracy, the machined parts are often brought into contact with each other (including pressure contact), and beam welding or the like is often performed.

  Such welded processed parts are usually parts subjected to machining such as grinding (cutting or polishing) while processing oil is supplied to the workpiece for the purpose of lubrication, cooling, rust prevention and the like. In order to stably weld such a processed part (appropriately referred to as a “welded part”), it is necessary to sufficiently remove chips, processing oil, and the like adhering to the surface before welding.

  In the case where the welded part is processed using a water-soluble processing oil, it may be possible to clean it using tap water, industrial water or the like as it is. However, simple water cleaning may result in insufficient cleaning of the processed part. Therefore, for example, the following patent document proposes cleaning the welded portion using a cleaning agent.

JP 2007-197610 A

  Patent Document 1 proposes to perform cleaning using a water-soluble cleaning agent having little welding inhibition before electron beam welding. However, the use of the cleaning agent causes poor welding due to the residue of the cleaning agent. Also, the use of a cleaning agent is not preferable because waste liquid treatment after cleaning also becomes a problem.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a welding method for an aluminum-based member that can reliably clean a welded portion without using a cleaning agent and reduce welding defects. And

  As a result of extensive research and trial and error, the present inventor has conducted a trial and error, and after cleaning a processed part machined with a water-soluble processing oil using alkaline electrolytic ionic water, the processed part is subjected to an electron beam. As a result of welding, it was newly found that desired welding can be stably performed. By developing this result, the present invention described below has been completed.

<< Welding method for aluminum-based parts >>
(1) The welding method of the aluminum-type member of this invention is a welding process which welds the aluminum-type members which have a process part which consists of aluminum or aluminum alloy and was machined using water-soluble processing oil between these process parts. A method of welding an aluminum-based member comprising: a cleaning step of cleaning at least the processed portion to be welded with alkaline electrolytic ionic water obtained by electrolyzing water before the welding step; And a drying step for drying the processed part.

(2) In the case of the aluminum member welding method of the present invention (simply referred to as “welding method”), since the cleaning agent is not used in the cleaning process before the welding process, the processed part before welding (the part to be welded) There is no residue caused by the cleaning agent. In addition, compared with washing with untreated normal water (tap water or industrial water), the water solubility attached to the welded part by using alkaline electrolytic ionic water (appropriately, simply referred to as “electrolytic ionic water”) is used. Processing oil can be removed more effectively. This is probably because emulsification of the water-soluble processing oil adhering to the welded portion is promoted by the electrolytic ion water. In any case, when the cleaning step according to the present invention is performed, no excellent residue is generated, and excellent cleaning performance that can reliably remove water-soluble processing oil and the like adhering to the welded portion is ensured. When the welding process is performed after this cleaning process, high-quality welding that stably secures the desired penetration depth while reducing blowholes caused by residues and residual dirt of water-soluble processing oil, etc. It becomes possible.

  The electrolytic ionic water used in the cleaning process according to the present invention can be obtained simply by electrolyzing tap water and the like, and since it does not use a cleaning agent, waste liquid treatment is easy. According to the welding method of the present invention, In addition, it is possible to reduce the cleaning cost and the welding cost.

<Others>
Unless otherwise specified, “x to y” in this specification includes a lower limit value x and an upper limit value y. A range such as “a to b” can be newly established with any numerical value included in various numerical values or numerical ranges described in the present specification as a new lower limit value or upper limit value.

It is a perspective view which shows the welding member which carried out the electron beam welding of the Al-type member. 5 is a graph showing the penetration depth at each part of the welded member according to Sample 1. FIG.

  One or two or more components arbitrarily selected from the present specification may be added to the above-described components of the present invention. Since the components relating to the manufacturing method can be understood as product-related claims as product-by-process claims, the contents described in this specification are not limited to the welding method of the present invention, and the aluminum-based material obtained thereby. It can also be applied to a welded member. Note that which embodiment is the best depends on the target, required performance, and the like.

《Cleaning process》
(1) The washing | cleaning process which concerns on this invention is a process of wash | cleaning at least the process part (to-be-welded part) welded with electrolytic ion water. There are various cleaning methods. For example, the machined aluminum-based member (appropriately, simply referred to as “Al-based member”) may be cleaned by immersing it in a cleaning tank containing electrolytic ionic water. It is preferable that the welded portion is easily maintained in a clean state, and if it is washed away by showering or spraying of electrolytic ionic water, welding is performed while suppressing the amount of electrolytic ionic water used. The entire processing part can be cleaned efficiently.

(2) The electrolytic ion water is preferably pH 8 to 11, and further pH 8.5 to 10.5. If the pH is too low, the cleaning power becomes insufficient. If the pH is too high, scales such as aluminum hydroxide adhere to the welded portion after cleaning, which is not preferable. In addition, the electrolytic ion water has a chloride ion concentration of 15 mg / L or less, a sulfate ion concentration of 20 mg / L or less, or a chloride ion concentration and a sulfate ion concentration of 2/2, respectively, compared with the raw water used for electrolysis. It is preferable that it is 3 or less. This is because if these anions are contained in a large amount in electrolytic ionic water, chlorides and sulfuric acid compounds are formed in the welded part, thereby inhibiting welding. Moreover, it is preferable that electrolytic ion water has a calcium concentration of 10 mg / L or less. When a large amount of calcium is contained in the electrolytic ion water, a scale such as calcium hydroxide adheres to the welded portion, which is not preferable.

  Furthermore, the electrolytic ion water is preferably 30 to 60 ° C., and more preferably 35 to 50 ° C., in order to improve the detergency. If the temperature is too low, the effect of improving the cleaning property is poor, and if the temperature is too high, workability and energy efficiency are reduced.

<< Drying process >>
The drying process according to the present invention is a process of drying the processed part after the cleaning process before the welding process. There are various drying methods, and it can be performed by natural drying, heat drying, warm air drying, air blowing, or the like. A plurality of drying methods may be combined. For example, after draining with an air blow after the washing step, drying is further performed with warm air to ensure drying.

《Welding process》
The welding process according to the present invention is a process of welding the processed parts (processed surfaces) cleaned of the Al-based members to be joined by contacting, contacting, butting, and the like. There are various welding methods. For example, high-precision welding is possible by performing electron beam welding performed by irradiating an electron beam between processed parts or laser welding performed by irradiating a laser between processed parts. In particular, when the welding process according to the present invention is an electron beam welding process, it is possible to obtain a large penetration depth while reducing the bead width (melting cross-sectional area), as well as improving energy efficiency and thermal influence on the surroundings ( Strain) is preferably suppressed.

<< Aluminum-based parts >>
The Al-based member according to the present invention may be any of a cast member, a forged member, an extruded member, etc. regardless of the manufacturing method. The composition thereof is not limited. For example, like a cast material, an Al-based member is 100% by mass (simply referred to as “%”) as a whole, and silicon (Si) is 5% or more, further 8% or more. The aluminum alloy is preferably included. In this case, the electrolytic ionic water supplied in the cleaning step easily spreads on the surface of the welded portion, and is expected to improve the cleanability and weldability with the electrolytic ionic water. The reason for this is not clear, but it is considered that the electrolytic ion water reacts with Si on the surface of the welded portion to form silicic acid to a slight extent.

  As an example of the composition of such an aluminum alloy, there are cases where Si: 8 to 13%, further 9 to 12%, Cu: 1 to 4%, or 1.5 to 3.5%, and the balance being Al and impurities. is there. The Al-based member having such a composition is particularly preferably a casting (die casting) material.

<Application>
There is no limitation on the type and application of the Al-based member joined by the welding method of the present invention or the welded member. An example is a member used in an automobile (automatic) transmission.

  By showing the case where the machined Al-based member is welded after washing with electrolytic ion water (Example), and the case where it is welded after washing with tap water (Comparative Example), the present invention is further improved. This will be specifically described.

<Production of sample>
(1) Al-based member As the Al-based member to be welded, two types of die-cast members made of an aluminum alloy (JIS ADC12) were prepared. These die cast members were cut using a water-soluble processing oil (Noritake Cool Series ES-20KP / Emulsion Type manufactured by Noritake Company Limited). Thus, a ring-shaped member A (inner diameter φ171 × H55 mm) and a disk-shaped member B (outer diameter φ171 × height 52 mm) were obtained (see FIG. 1).

(2) Washing process The electrolytic ion water produced | generated with the Takahashi metal Co., Ltd. ion water production | generation apparatus (TIWS-IW06C) was prepared. This electrolytic ion water had a pH of 9.35, a chloride ion concentration of less than 0.1 mg / L, a sulfate ion concentration of less than 0.1 mg / L, and a calcium concentration of less than 0.1 mg / L.

  Using the electrolytic ion water and tap water, the above-described processed members A and B (both are collectively referred to as “work”) were washed. This washing was performed for about 30 seconds by spraying each water at 40 ° C. (water pressure 0.4 MPa) from a shower nozzle onto each workpiece placed on a belt conveyor at a conveyance speed of 2 m / min.

(3) Drying process Each work after the cleaning process placed on the belt conveyor at a transfer speed of 2 m / min is drained by air blow until there is no water drop, and then the surface of the work is blown with 100 ° C hot air. Was dried.

(4) Welding process The inner peripheral surface (processed part) of member A was fitted (press-fit) to the outer peripheral surface (processed part) of member B after the drying process. Electron beam welding was performed from the member B side to eight equal positions on the annular fitting portion (welded portion) thus formed. This is shown in FIG. Electron beam welding was performed using an electron beam processing machine manufactured by Tada Electric Co., Ltd. At this time, the beam current was 43 mA and the beam moving speed was 1 m / min in the sample 1, and the beam current was 78 mA and the beam moving speed was 3 m / min in the sample 2.

<< Observation / Measurement >>
(1) Wettability On the surface of the workpiece before cleaning and on the surface of the workpiece after cleaning, ink ink was dropped and the extent of spreading (wetting) was observed. Before washing, the ink was not bounced and spread by the processing oil adhering to the work surface. On the other hand, in the case of washing, the ink spread wet without spreading on the workpiece surface. This tendency was almost the same when electrolytic ion water was used as cleaning water and when tap water was used.

(2) Detergency The surface of the workpiece washed with electrolytic ion water and tap water was wiped off with a cotton swab, and the degree of washing was observed. In this case, the surface of the workpiece cleaned with electrolytic ion water was less contaminated with the cotton swab than the surface of the workpiece cleaned with tap water.

(3) Weldability For each workpiece (welded member) welded after washing with electrolytic ion water or tap water, 8 welds were cut, and the penetration depth and the number of blowholes were measured. For Sample 1, the penetration depth at each site (position) in each case is shown in comparison with FIG. Moreover, the average values of the penetration depths when washed with electrolytic ion water and when washed with tap water are 8.12 mm and 7.45 mm for sample 1 and 8.45 mm for sample 2 respectively. And 8.01 mm. The standard deviations were 0.19 and 0.27 for sample 1 and 0.14 and 0.41 for sample 2, respectively.

  The number of blowholes related to sample 1 is 7.75 on average when washed with electrolytic ion water and welded, and 0.95 per 1 mm, and may be welded after washing with tap water. The average number was 8.75 and the number of occurrences per mm was 1.17. In addition, the number of blowholes related to Sample 2 was 8.75 on average when washed with electrolytic ion water and welded, and 1.04 per mm, and was welded after washing with tap water. The average number of cases was 8.63, and the number of occurrences per mm was 1.08.

<Evaluation>
(1) It was confirmed that the surface of the welded portion can be cleaned more cleanly by washing the welded portion with electrolytic ion water before welding than by washing with tap water.

(2) As is clear from the above-described contents and FIG. 2, when welding a welded portion made of a machined surface washed with electrolytic ion water, a greater penetration depth is obtained at each welded site than when washed with tap water. It was found that it can be obtained stably.

(3) The same can be said for the number of blow holes. In other words, it was found that the number of blowholes in the welded portion can be reduced and the high-quality (electron beam) welding can be stably performed when washing with electrolytic ion water as compared with washing with tap water.

(4) It should be noted that the effect of improving the weldability by pre-cleaning the welded portion with the electrolytic ion water can be understood from the comparison of the sample 1 and the sample 2, when the beam moving speed is small, as well as the beam moving speed. It was also found that the same effect can be obtained by increasing.

Claims (6)

A welding method for an aluminum-based member comprising a welding step of welding aluminum-based members made of aluminum or an aluminum alloy and having machined parts machined using a water-soluble processing oil between the processed parts,
Before the welding process, at least the processed part to be welded is washed with alkaline electrolytic ionic water obtained by electrolyzing water, and
A drying step of drying the washed processed part;
A method for welding an aluminum-based member, comprising:   The method for welding an aluminum-based member according to claim 1, wherein the cleaning step is a step of washing the processed portion with the alkaline electrolytic ionic water.   The method for welding an aluminum-based member according to claim 1 or 2, wherein the alkaline electrolytic ionized water has a pH of 8 to 11.   The said alkaline electrolytic ion water is 30-60 degreeC warm water, The welding method of the aluminum-type member in any one of Claims 1-3.   The aluminum-based member welding method according to any one of claims 1 to 4, wherein the aluminum-based member is made of an aluminum alloy containing 5% or more of silicon (Si) as a whole by 100 mass% (simply referred to as "%"). .   The said welding process is an electron beam welding process performed by irradiating an electron beam between the said process parts, The welding method of the aluminum-type member in any one of Claims 1-5.

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