JPH0227302A - Stock for reflecting mirror made of aluminum alloy - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an aluminum alloy reflective mirror material.

(Prior art) For example, in OA equipment and measuring instruments such as laser printers, so-called polygon mirrors, which have a mirror surface on the outer peripheral surface of a prismatic body and are driven in positive rotation, are used in order to scan laser light with high precision. There is.

A polygon mirror such as the one shown in item 2 is required to have high reflectance for highly accurate scanning of laser light, and is also required to be lightweight in order to reduce the size and capacity of rotary drive equipment.

Therefore, polygon mirrors are manufactured by ultra-precision processing of aluminum alloy materials.

Conventionally, the polygon mirror is made of aluminum, magnesium, and impurities that can be avoided underground such as Cr, Mn, and Si.
A mirror surface was obtained by casting an alloy consisting of , Fe, Ti, etc. into a prismatic material, and performing ultra-precision processing with a diamond cutting tool.

(Problems to be Solved by the Invention) Conventional aluminum alloy reflecting mirror materials were cast materials, and the aluminum base metal was required to have a high purity of 99.99% or more. This is to prevent elements that have an affinity with diamond bites, elements that have an adverse effect on the mirror surface, from precipitating and reducing the reflectance during casting.

However, it is uneconomical to use high-purity aluminum metal, and the present invention aims to solve this problem.

(Means for Solving the Problems) The present invention is characterized by a compression molded material of rapidly solidified aluminum alloy powder, in which the aluminum alloy contains Mg: 0.5 to 10% by weight, Ce: 0.1 ~1% by weight, the balance being Al and impurities, and can be used as a reflecting mirror by being mirror-finished.

(Function) Rapidly solidified aluminum alloy powder has a higher solid solubility limit than cast materials, and can dissolve elements that have an affinity for diamond bites and elements that adversely affect mirror surfaces in a supersaturated state, so aluminum ingots have high purity. It doesn't have to be.

However, on the surface of rapidly solidified aluminum alloy powder, #
A film of oxides such as tO and MgO is formed, and this film becomes more ductile by absorbing water. Then,
When alloy powder is compression-molded to form a reflector material, the oxide film prevents the powder from diffusing and powder grain boundaries remain. Such powder grain boundaries reduce the reflectance of the mirror surface.

Therefore, by adding Ce, which is more easily oxidized than Al and Mg, # and Mg are prevented from oxidizing and forming a film.

If the amount of Ce added is less than 0.1%, the oxidation of At and Mg cannot be sufficiently inhibited, and if it exceeds 1%, the oxidation is only consumed, and the effect of inhibiting the oxidation of Af and Mg is no longer constant.

Mg is added to improve strength; if it is less than 0.5%, sufficient strength cannot be obtained, and if it exceeds 10%, workability deteriorates.

(Example) Tables 1 and 2 below show experimental results that serve as the basis for limiting the composition of Ce and Mg.

(Next leaf) Table 1 Table 2 Each of the above materials is made by rapidly solidifying aluminum alloys of the respective compositions into powder using water atomization method, air atomization method, etc., and extruding it into a prismatic reflecting mirror. This is the material used. The material was then mirror-finished using an orbiting single-crystal diamond tool to create a polygon mirror, and its reflectance was investigated.

Moreover, FIGS. 1 to 3 are enlarged photographs (300 times) of the cross-section of the reflecting mirror material, and the amount of Ce added is less than 0.1% by weight in FIG. 1, and in FIG. 0.1 for
Weight %, exceeding 0.1 weight % in Figure 3, 1 weight %
less than

In each of these figures, it can be seen that the number of white line-shaped powder grain boundaries is smaller in species with a larger amount of Ce added.

In addition, the rapid solidification rate during powderization of N alloy is 104 to 1
The temperature was set at 0'°C/sce. In addition, the purity of N metal is 99.7
% or more is sufficient.

The extrusion conditions for the rapidly solidified N alloy powder are as follows: extrusion temperature is 300~
For 500″c1 extrusion, the number was 2 or more.

Note that forging may be used instead of extrusion, and the powder may be dispersed by compression.

(Effects of the Invention) Since the aluminum alloy reflector material according to the present invention is a compression molded material of rapidly solidified powder with a high solid solubility limit, there is no need to use high-purity Mo9 as the aluminum base metal, and C
The addition of e prevents the formation of an oxide film on the powder surface,
It is possible to prevent powder grain boundaries from remaining during compression molding, and it is possible to economically prevent a decrease in mirror reflectance.

[Brief explanation of the drawing]

Figures 1 to 3 are enlarged photographs of the metal structure of the cross-section of the reflecting mirror material. Addition amount is 0.1
-%, the one in Figure 3 has an added amount of Ce of 0. It is more than Iev% and less than 1w%. dormitory, f t, n2

Claims (1)

[Claims] (1) A compression molded material of rapidly solidified aluminum alloy powder, the aluminum alloy is composed of Mg: 0.5 to 10% by weight, Ce: 0.1 to 1% by weight, the balance being Al and impurities, and mirror-finished. An aluminum alloy reflective mirror material that is characterized by being used as a reflective mirror.