MOULD COATING METHOD The Related Art

The invention relates to the mould coating method, in which all of the mould, core, and bench-mould connection pieces and etc. mould pieces are coated by using coating powders in order to prevent the aluminium that is molten in high temperatures from causing damage on the moulding by being welded, soldered on mould surface.

The Prior Art In basic mould casting methods, filling of the material into the mould is ensured via gravity. In low pressure casting, liquid metal is filled into mould from bottom to top via low pressure. Advantage of this method against conventional casting methods is: the liquid metal filling into the mould from a chamber being cleaner than the liquid metal open to atmosphere. In this way, while gas pores and oxidation are minimized, mechanical properties are improved.

The most important and fundamental two inputs of rim production conducted by using Conventional Low Pressure Casting Method are: "aluminium alloy and mould". Rim production with Low Pressure Casting Method is based on filling of the aluminium alloy molten at 750°C - 800°C into mould with the help of pressure and solidification via cooling by force.

One of the significant problems causing increase of wastage and scrap and loss of efficiency and labour is "soldering". Soldering is defined as the molten aluminium causing damage on the mould via "welding", adhering on it.

There are two different formation types of the soldering mechanism: 1 ) Chemical/metallurgical reaction between the aluminium molten at high temperature and the mould, and

2) Mechanical interaction at low temperature.

At the sub-cores, chemical/metallurgical reactions are encountered between the aluminium molten at high temperature and the mould. In the applications, it is determined that the soldering problem occurs after the 50 ^th -100 ^th pieces after starting of the casting of mould.

Said problems directly affect the finished product quality and cause them to be wastage and scrap. As a result of these problems, production is halted and levelling operations are applied on the relevant areas on the mould. If levelling operations are inadequate, the cavitations formed are filled via welding.

Swellings occur at the welded areas. Therefore, adequate efficiency is not obtained from welding operation. After a certain number of usages, the mould becomes useless. Efficiency losses occur in production due to soldering problem. Moreover, the unit costs per finished product increase as a result of production of extra moulds. Direct and indirect costs occur.

As a result, above said drawbacks and the inadequacy of the prior solutions about the subject have necessitated improvement in the related technical field.

Purpose of the Invention

The invention is formed by being inspired from the prior art and aims to solve above said problems.

The purpose of the invention is to prevent reaction of the moulds with the molten liquid aluminium by coating of the moulds in order to eliminate the soldering problem occurring in the productions made with aluminium casting method.

Another purpose of the invention is to prevent reaction of the moulds with the molten liquid aluminium by coating of the moulds in order to eliminate the soldering problem after determination of the coatings having high abrasion resistance and thermal shock resistance.

Another purpose of the invention is to reduce bench stoppage.

Another purpose of the invention is to increase usage of capacity.

Another purpose of the invention is to increase production efficiency. Another purpose of the invention is to provide reduction of the unit cost per finished product. ,

In order to achieve above said purposes, the invention relates to mould coating method, in which all of the mould, core, and bench-mould connection pieces and etc. moulding are coated by using coating powder in aluminium alloy casting method in order to prevent the aluminium that is molten in high temperatures from causing damage on the moulding by being welded, soldered on mould surface. The structural and characteristic features of the invention and all advantages will be understood better in detailed descriptions with the figures given below and with reference to the figures, and therefore, the assessment should be made taking into account said figures and detailed explanations. Figures for Better Understanding of the Invention

Figure 1 - is the flow scheme showing the operation steps of mould coating method.

Description of the Parts References

10. Moulding

1 1. Sandblasted moulding

12. Coated moulding

20. Sandblasting device

30. Coating device

31. Coating powder Drawings do not have to be scaled and details not necessary for understanding the present invention may be neglected. Moreover, components which are at least widely equal or which have at least widely equal functions are shown with the same number.

Detailed Description of the Invention In this detailed description, the operation steps of the mould coating method applied by using coating powder (31) on all mould, core, and bench-mould connection pieces and etc. moulding (10), which is the subject of the invention, are disclosed.

The invention is the mould coating method, in which the moulding (10) is coated by using coating powder (31 ) in aluminium alloy casting method in order to prevent the aluminium that is molten in high temperatures from causing damage - on the moulding (10) by being welded, soldered on all mould, core, and bench- mould connection pieces and etc. moulding (10) surfaces, and it is characterized in that; it comprises the operation steps of:

- visual examination of moulding (10), getting the moulding (10) into sandblasting process and thus sandblasting of all surfaces to be coated via sandblasting device (20), and

coating of the moulding (10) by coating powder (31 ) formed of chrome, nickel, tungsten, tantalum, and cobalt metals.

First of all, visual examination of mould, core, and bench-mould connection pieces etc. moulding (10) coming from the customer are made. Afterwards, moulding (10) is taken into sandblasting. In order to provide good adherence of coating, all surfaces to be coated are sanded. After sandblasting operation, the moulding (10) is taken into coating cabinet and via the coating device (30) controlled coating is applied with the coating powder (31 ) mixture which is prepared in accordance with the operation medium of the surface to be coated. The piece determined to have reached the appropriate coating thickness as a result of measurement is taken to the waiting area for shipment.

In the mould coating method, as a result of digital monitoring of number of productions, it is determined that soldering-free casting can be made up to 5000 items according to the mould design and model. After 5000 items, pottage operation is renewed on coating. Pottage is the refractor based sodium silicate solution preventing the applied and casted piece from adhering on these surfaces and also helping directional solidification of the liquid metal. In the ' operation made during removal of the remaining pottage from the surface, deformed coatings as a result of being damaged are removed from the surface. Since there is no abrasion in the mould, the same moulding (10) is made ready for use by coating operation.

The invention is the coating powder (31 ) used in mould coating in aluminium alloy casting method, wherein moulding (10) is coated in order to prevent the aluminium that, is molten in high temperatures from causing damage on the moulding (10) by being welded, soldered on all mould, core, and bench-mould connection pieces and etc. moulding (10) surfaces, and it comprises chrome, nickel, tungsten, tantalum and cobalt metals.

Coating powder (31 ) comprises chrome, nickel, tungsten, tantalum, and cobalt metals in the ratio by mass of;

65% - 85% Chrome (Cr)

18% - 39% Nickel (Ni)

1 % - 15% Tungsten (W)

0.007% - 0.980% Tantalum (Ta)

0.1 % - 0.93% Cobalt (Co).