JPH03128164A - Production of ti or ti alloy casting - Google Patents

Abstract

PURPOSE:To easily produce a thin hollow member having excellent dimensional accuracy by casting a hollow casting having many ribs on the outside surface at a target wall thickness, and then cutting away the ribs at the time of producing the thin hollow member consisting of Ti or Ti alloy. CONSTITUTION:The melt of the Ti or Ti-Al-V alloy, etc., is cast by a casting method, such as lost wax method, to produce the hollow casting 1 which has the final wall thickness of t1 and is provided with the many ribs 2 having the thickness t2 of 0.3 to 3 times the t1 and the width w1 of 0.5 to 5 times the t1 on the outside surfaces thereof at intervals w2 of 0.5 to 5 times the w1. Only the ribs 2 on the outside surface are then removed by working, such as grinding or cutting, by which the thin hollow Ti casting or Ti alloy casting 3 having the excellent dimensional accuracy is easily produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing Ti (titanium) or Ti alloy castings, and in particular to a Ti or Ti alloy suitable for manufacturing thin-walled hollow castings using Ti or Ti alloys. This invention relates to a method for manufacturing castings.

[Prior Art] In recent years, Ti or Ti alloys have come to be widely used as materials for golf heads, etc., but for example, for golf heads, it is necessary to reduce the weight by thinning the walls, and
There is a strong desire to improve dimensions, weight, and shape accuracy, and to eliminate variations in product quality.

By the way, thin-walled hollow castings made of Ti or Ti alloy, such as golf heads, are mainly manufactured by a lost wax method or the like. In this case, since Ti has a high melting point, T
Casting of Ti alloys containing a large amount of i and Ti requires heating at high temperatures. However, since Ti is highly active, when a molten metal of Ti or a Ti alloy is heated to a high temperature, the molten metal and the mold will react. For this reason, conventional casting methods cannot heat Ti or Ti alloy molten metal to a sufficient degree to ensure sufficient swirling properties, and the molten metal has poor swirling flow, and thin-walled hollow castings are made using the lost wax method etc. It was difficult to manufacture. For this reason, conventionally, when manufacturing thin-walled hollow castings made of Ti or Ti alloy, a hollow casting 11 with a uniformly thick wall thickness is cast as shown in FIG. 2(a), and then a As shown in FIG. 2(b), the outer surface was uniformly ground to reduce the thickness and form a thin-walled hollow casting 2.

[Problems to be Solved by the Invention] However, the above conventional method has the following problems.

■ Machining is time consuming as the entire surface of the casting is ground.

■ Processing the entire surface of a casting uniformly is an extremely difficult task, and it is difficult to manufacture products with high precision in shape, size, and weight.

■ In the case of (7) Ti alloys such as Ti-6All-4V, cooling becomes insufficient due to the thickening of the casting, resulting in coarsening of crystal grains and deterioration of mechanical properties such as strength and toughness of the casting. do.

(2) When producing a hollow casting with a simple shape such as a golf head using the lost wax method, deformation of the wax, mold, and casting tends to occur, making it difficult to produce a casting with a predetermined size and shape.

[Means for Solving the Problems] The method for producing a Ti or Ti alloy casting of the present invention is to produce a thin-walled hollow casting of Ti or a Ti alloy by using a casting having ribs on the outer surface in accordance with the intended shape of the casting. After manufacturing, the ribs of the casting are removed to form the casting into the desired shape.

[Function] According to the method of the present invention, leakage flow during casting is improved. In addition, the precision of the product is improved and the crystal grains are also made finer.

[Examples] Examples of the present invention will be described in detail below with reference to the drawings.

FIGS. 1(a) and 1(b) are cross-sectional perspective views illustrating an embodiment of the method for manufacturing Ti or Ti alloy castings of the present invention.

As shown in the figure, in order to manufacture a thin-walled hollow casting of Ti or Ti alloy by the method of the present invention, first, ribs are formed on the outer surface according to a normal hollow casting manufacturing method such as the lost wax method.
A hollow casting 1 having the following structure is manufactured (FIG. 1(a)). Then, the protrusion 2 of the hollow casting 1 is removed by grinding, cutting, etc. to obtain a thin hollow casting 3 having the desired shape.

Therefore, in the present invention, the wall thickness tl of the portion of the hollow casting 1 manufactured by casting where the ribs 2 are not formed is set equal to the wall thickness of the thin hollow casting 2 having the desired shape, and the ribs 2 are removed. Thus, a thin-walled hollow casting 3 having the desired wall thickness can be obtained.

In addition, in the present invention, there are no particular restrictions on the location where the ribs are formed, the direction in which they are formed, and the height t2 and width W+ of the ribs, which are determined as appropriate depending on the thickness, shape, size, alloy composition, etc. of the product casting. . In normal cases, the cross-sectional shape of the rib is determined by the thickness of the product casting,
In other words, the height t2 is approximately 0.5 to 3 times the height tl, and the height t2 is 0.5 to 3 times the height tl.
The ribs have a substantially trapezoidal shape with a width W+ of about 5 to 5 times, and the interval W2 of such ribs is 0.5 to 0.5 to the width W of the rib.
Although it is preferable to arrange Ti alloys in parallel so that the number of Ti alloys is five times as large, there is no particular restriction on the Ti alloy suitable for the method of the present invention.
Effective for casting alloys containing 60% by weight or more. Specific examples of Ti alloys suitable for the method of the present invention include, for example:
Ti-6Af1. -4V, Ti-6AJl-6V-2S
n.

Ti-13V-11Cr-3AIL, Ti-11,5
Mo-62r-4,5Sn, Ti-5Hafu-2,5S
Examples include n.

The method of the present invention is particularly suitable for manufacturing golf heads made of Ti or Ti alloy, and can produce thin, lightweight golf heads with high dimensional accuracy, shape accuracy, and weight ffi accuracy without any variation from product to product. , it is possible to manufacture it efficiently.

Specific examples and comparative examples are listed below.

Example 1 A Ti alloy (composition:
A thin-walled hollow casting of Ti-6Ai-4V) was manufactured.

That is, first, a hollow casting with ribs having the following shape was manufactured by the lost wax method.

In Figure 1, the thickness of the part other than the lip tI: 1.6 mm The height of the rib t2: 0.8 mm The width of the rib W1: 5 mm The distance between the ribs W2: 10 mm After that, the ribs were removed by grinding, and the following shape was obtained. A thin-walled hollow casting was manufactured.

External dimensions: 100x60x40mm Internal dimensions: 96.8X56.8X36.8mm Thickness: 1.6
mm 100 castings were manufactured using this manufacturing method, and their dimensions, weight, and shape accuracy were extremely high, and there was almost no variation from product to product.

Comparative Example 1 The same composition as Example 1 was prepared according to the conventional method shown in FIG.
A thin-walled hollow casting made of Ti alloy having the same shape was manufactured.

That is, first, a thick hollow casting having a uniform constant thickness of 3 mm was manufactured, and then the surface was uniformly processed by grinding to obtain a thin hollow casting.

As a result, 30 out of 100 castings were found to be defective because their dimensions, weight, and shape were significantly different from the standard.

[Effects of the Invention] As described above, in the method of the present invention, (1) By providing the ribs, the mold space becomes larger and the swirling properties of the molten metal are improved.

■ The provision of ribs increases the surface area of the casting and increases the cooling rate. Therefore, coarsening of crystal grains does not occur, and a casting with fine crystal grains can be obtained.

■ Since the ribs serve as reinforcing parts to prevent molds and castings from deforming, there is less deformation of wax patterns, molds, and castings even in the lost wax method, and castings with high dimensional, weight, and shape accuracy can be obtained.

■ It is easy to process as only the ribs need to be removed. In addition, it is easy to control the thickness of the portion where no ribs are provided.

As a result, products with high precision in size, shape, and weight can be easily obtained, and variations among products are also reduced.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional perspective view illustrating a method of manufacturing a Ti or Ti alloy casting according to the present invention, and FIG. 2 is a cross-sectional perspective view illustrating a conventional method. 1...Hollow casting with ribs, 2...Ribs, 3...Thin hollow casting.

Claims (1)

[Claims] (1) When manufacturing thin-walled hollow castings of Ti or Ti alloys, after manufacturing a casting that has ribs on its outer surface in accordance with the desired shape of the casting, the ribs of the casting are removed to obtain the casting of the desired shape. A method for producing a Ti or Ti alloy casting, characterized by: