AU2011100237B4 - Method, System and Apparatus for Indicating Wear - Google Patents

Abstract

The present invention provides a method of determining wear of a wear product (10) comprising protective material (1,2) adapted for lining a machine part, the method comprising the steps of: varying at least one physical property of the protective material (1,2) as a function of depth from an outer exposed surface (3) of the protective material (1,2); remotely sensing a change in the physical property as the outer exposed surface (3) propagates into the protective material (1,2) in the course of use.

Description

P1/00/002 Regulation 3.2B AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION INNOVATION PATENT Application No. Lodged: Innovation Title: Method, System and Apparatus for Indicating Wear The following statement is a full description of this innovation, including the best method of performing it known to the Applicant, : 2 METHOD, SYSTEM AND APPARATUS FOR INDICATING WEAR FIELD OF INVENTION This invention relates to the field of wear resistant materials and more particularly to providing an indication of wear in such materials that form wear 5 products utilised as component parts of machinery and equipment for extracting and handling mineral resources and like raw materials, for example, in the mining and excavation industry. In one form, the invention relates to ceramic composite materials used for wear resistance and it will be convenient to hereinafter describe the invention in relation to the use of alumina ceramic plates, tiles or 10 cubes for use in the area of mining and raw materials handling, however it should be appreciated that the invention is not limited to that use, only. BACKGROUND ART Throughout this specification the use of the word "inventor" in singular form may be taken as reference to one (singular) inventor or more than one (plural) 15 inventor of the present invention. It is to be appreciated that any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the present invention. Further, the discussion throughout this specification comes about due to the realisation of the inventor and/or the identification of certain related art 20 problems by the inventor. Moreover, any discussion of material such as documents, devices, acts or knowledge in this specification is included to explain the context of the invention in terms of the inventor's knowledge and experience and, accordingly, any such discussion should not be taken as an admission that any of the material forms part of the prior art base or the common general 25 knowledge in the relevant art in Australia, or elsewhere, on or before the priority date of the disclosure and claims herein. Hardened materials, traditionally those such as steel and steel alloys, have been used to reduce wear on structural elements of machinery and/or equipment utilised for handling raw resource materials, for example, ores, rocks etcetera, 30 which can be highly abrasive to the equipment by exposure to wear in the form of sliding and/or gouging abrasion from the moving material. Wear products make use of these hardened materials, often in the form of plates, tiles or cubes and are called wear plates, wear tiles etcetera because the material of the plate, tile 3 cube etcetera is selected for its resistance to wear. It is to be understood that for the purposes of description herein, wear plates, tiles, cubes and the like which form discrete elements that are applied to machines and machine parts for the purpose of reducing wear in machinery for mining and raw materials handling will 5 be referenced by the term "wear product". Wear products are also known to be made of other materials, such as rubber and ceramics or may be composites of these materials. Some example equipment which makes use of wear products etcetera include hoppers, bins and chutes used in rock handling equipment and in mineral ore processing. Another example of use of wear products is in their 10 positioning in and around excavating teeth that are disposed on the ground engaging edge of buckets for instance, or at the cutting edge of dredgers. The wear resistant materials of the wear products act as a sacrificial element so that the products are worn rather than the structural portions of the equipment or machinery per se. Generally, the wear products can be readily exchanged once 15 worn, thus extending the life of the working equipment and machinery. Ceramic and composite material wear protection products, in comparison to conventional metallic wear products have been known to provide longer wear, improved cost effectiveness and may also reduce certain safety hazards associated with metallic products. They are often used for applications such as 20 mining and related engineering in the form of tiles & cubes. One particular form of ceramic composite product is alumina ceramic tiles, which comprises Aluminium Oxide (A1 2 0 3 ) as the substantial component of the material in a wear protection product. Alumina, in general, offers a combination of good mechanical properties and electrical properties leading to a wide range of applications. 25 Further, it may be used as an abrasive due to its hardness and as a refractory material due to its high melting point. It is also noted that these properties make alumina ceramic materials suitable for wear protection. Further, alumina can be produced in a range of purities with additives designed to enhance its useful properties. A wide variety of ceramic processing methods can be applied 30 including machining or net shape forming to produce a wide variety of sizes and shapes of component. In addition it can be readily joined to metals or other ceramics using metallising and brazing techniques and can be utilised in weldable and non weldable applications.

4 Much emphasis is placed on ensuring the wear lining material in many engineering and industrial applications is always present so as to not damage the underlying parent metal of the fixed plant structure of the equipment or machinery. However, the wear lining material will wear away and in the event 5 protective wear material is worn to the extent the parent structure is exposed this calls for shut down of plant to undergo maintenance and replacement of the wear protection material and in extreme cases also replacement of the equipment and machinery through damage. The key to efficient operation is to avoid damage to the equipment itself but also to retain awareness of the state of the wear 10 protection elements. To this end, no quick and simple indication of wear is available on the market for this type of wear protection material, particularly in significant mining applications. Current generally accepted practice being used for providing an indication of wear in wear protection materials is undertaken by handheld portable 15 ultrasonic thickness testing equipment. However, such an operation requires the processing plant to be shut down and personnel to enter the area of testing, which is normally a confined space, to test each liner material individually. Further, confined space permits are required, in which specialized labour may be required which, is time consuming due to individual testing. Scaffold work 20 platforms may be required to be erected in some areas to gain full access. A further onerous requirement may be extended plant shut down during manual testing, etc. These known techniques and processes for providing information and indications of wear can provide for accurate measurement of thickness, 25 However, at the very least they may be time consuming and may introduce increased safety risks due to personnel being required to enter into inside confined space within a fixed plant, for example. SUMMARY OF INVENTION It is an object of the embodiments described herein to overcome or 30 alleviate at least one of the above noted drawbacks of related art systems or to at least provide a useful alternative to related art systems. In one aspect the present invention provides a method of determining wear of a wear product in the form of discrete tiles, plates, cubes or the like, the wear 5 product comprising protective material and being adapted for lining a machine part utilised for handling raw materials, the method comprising the steps of: varying at least one physical property of the protective material as a function of depth from an outer exposed surface of the protective material; 5 remotely sensing a change in the physical property as the outer exposed surface propagates into the protective material in the course of use In a first aspect of embodiments described herein there is provided a method of determining wear of a wear product comprising protective material adapted for lining a machine part, the method comprising the steps of: 10 varying at least one physical property of the protective material as a function of depth from an outer exposed surface of the protective material; remotely sensing a change in the physical property as the outer exposed surface propagates into the protective material in the course of use. In accordance with preferred embodiments of the present invention the 15 variation in the physical property of the protective material that provides the advantage of the present invention may be brought into effect by a number of means including but not limited to varying the chemical composition of the wear product or providing a change in morphology of the protective material, In another aspect the present invention provides a wear product in the 20 form of a discrete tile, plate, cube or the like, the wear product comprising a protective material and being adapted for lining a machine part utilised for handling raw materials, the protective material comprising at least one physical property that varies as a function of depth from an outer exposed surface of the protective material, wherein as the outer exposed surface propagates into the 25 protective material in the course of use a change in the physical property is remotely sensed to provide an indication of wear of the wear product. In another aspect of embodiments described herein there is provided a wear product comprising a protective material adapted for lining a machine part, the protective material comprising at least one physical property that varies as a 30 function of depth from an outer exposed surface of the protective material, wherein as the outer exposed surface propagates into the material in the course of use a change in the physical property is remotely sensed to provide an indication of wear of the product.

6 In preferred forms the varying physical property comprises one or a combination of: visual appearance; audible perception; 5 mechanical vibration. Furthermore, it is preferred that the step of varying at least one physical property of the protective material comprises one of: a step change in physical property; a gradual change in physical property; 10 a graduated change in physical property. In a particularly preferred embodiment the varying physical property comprises a change in colour of the material. As would be understood by the person skilled in the art, once the present invention is grasped, detecting a change in the physical property at the step of 15 remotely sensing may provide an indication that the protective material is: worn to a point where it requires replacement; or worn to a point where it will imminently require replacement. Preferably the protective material comprises one or a combination of: a ceramic; 20 a metal; a rubber; a composite ceramic; a composite ceramic including metal or rubber. In preferred embodiments the protective material forms one of a wear 25 plate; a wear tile; or a wear cube. A wear product in accordance with preferred embodiments is formed such that the variation of the physical property of the protective material occurs at a depth of: between about 50% and 95% of the thickness of the protective material; or 30 between about 60% and 90% of the thickness of the protective material; or about 80% of the thickness of the protective material.

6a In yet a further aspect of embodiments described herein there is provided a method of fabricating a wear protection product adapted for providing self indication of its deterioration through use, the method comprising the steps of: introducing powdered protective material comprising a first physical 5 property of a first predetermined volume to a mould; forming a smooth surface of said protective material within said mould; introducing powdered protective material comprising a second physical property upon the smooth surface of protective material; compressing powder in the mould into a predetermined shape to form a 10 one piece green state item with a disparate layered structure; ejecting said green state item from mould; temperature processing said green state item to achieve sufficient physical and mechanical strength for use. Other aspects and preferred forms are disclosed in the specification and/or 15 defined in the appended claims, forming a part of the description of the invention. In essence, embodiments of the present invention stem from the realization that providing a physically varying profile to wear protection materials can provide for readily apparent remote determination of the state of wear of the material by a user at a safe distance from the operating front of machinery and 20 provide a predetermined warning that wear has exceeded or is about to exceed to a preferred extent thus obviating cost and safety drawbacks associated with current methods of determining the extent of wear in wear products. Advantages provided by the present invention comprise the following: Obviates the need for extended plant shut down; 25 7 * Saves cost of overly worn parts; e Assists with timely management of equipment and improves fixed plant maintenance program. * Avoids the likelihood of catastrophic failure of wear liner material 5 Further scope of applicability of embodiments of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the 10 disclosure herein will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS Further disclosure, objects, advantages and aspects of preferred and other embodiments of the present application may be better understood by those 15 skilled in the relevant art by reference to the following description of embodiments taken in conjunction with the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the disclosure herein, and in which: Figure 1 is a perspective view which illustrates a wear product in accordance with a preferred embodiment of the present invention; 20 Figure 2 is a side profile view of a wear product in accordance with a preferred embodiment of the present invention. DETAILED DESCRIPTION Protective wear products in the form of ceramic wear liners can be suitable for many different applications. Typically a tile or cube size, shape and layout will 25 be determined by the application's requirements. Wear liners, for instance, can be produced with cylindrical, hexagonal or rectangular ceramics of various sizes and thicknesses to provide optimal protection for equipment. Numerous fixing methods are available to enable installation in many situations and equally when replacing wear products there may be involved procedures to follow so reducing 30 the times it is required to make replacements would be desirable. Wear products such as lining systems etcetera may be provided in rubber, ceramic, ceramic only, rubber only, metal or combinations. These materials can be expensive to 8 replace and more so the time and labour involved in attending to replacement can be significant as can the effects such as down time. The problems identified by the inventor in related art systems in providing an indication of wear in wear products have been solved in one aspect of 5 embodiments of the present invention which provides for a different coloured alumina ceramic material layer within the same unitary piece of composite material utilised for wear protection. Accordingly, this provides an estimation of thickness as the material wears down. Preferred embodiments of the present invention provide solutions that 10 differ from previous attempts of related art noted above by virtue of providing an exclusively visual (or other physical) indication that obviates any need for personnel to intervene in the operations of heavy equipment and the required health and safety measures that this demands. The wear product of preferred embodiments provides for ease of thickness 15 inspection to confidently ensure wear liners are changed out prior to complete failure and possible damage to parent metal. Preferred wear liner materials of embodiments are a significantly less costly alternative to related art mechanisms such as routine inspection of equipment requiring plant shut down. Accordingly, they provide less plant down 20 time, and improved safety standards without the need to have personnel enter fixed plant chutes, for example. In one preferred embodiment, as shown in figures 1 and 2 a wear product is provided which comprises a composite ceramic being an alumina ceramic tile or cube 10 composed of about 92% to 95% alumina. Preferably a first wear 25 protection region 1 is a white coloured alumina. A second critical wear zone 2 has a different colour. This embodiment provides a wear product in which its composition provides for a solution as simple as the colour of the protective material changing from white in the useful region 1 of the product to a bright colour as the ceramic material wears down to the critical change out zone 2 or, 30 equally as this zone may be considered, in a wear indicating region 2. Alternatively, multi coloured layers of alumina ceramic material may be introduced into the product to provide a staged indication to a user of the state of wear. In an alternate embodiment, it is envisaged that the change in visual characteristic of 9 the wearing surface 3 as it propagates through the depth of the material may be detected by an optical sensor permanently or periodically pointed at the surface of the wear material to provide an indication of the state of wear for a user. The physical property that varies may be other than visual. For example, 5 the make up of the material could comprise a composite substance that whilst not causing physical damage could emanate a different or higher volume of sound to draw attention to an increasing or imminent wear state. Equally the material in the critical zone 2 could provide an increase in mechanical vibration that can be selected to be inert to the machinery but of significant ability to draw the attention 10 of humans to a change in the operation of the equipment and provide an indication of wear. Whilst the critical zone 2 is shown in figure 1 and 2 as a uniform region of material make up, the critical zone 2 could equally be provided as one of a step change in physical property as shown or, a gradual change or even a graduated 15 change in physical property along a depth profile. In figures 1 and 2 the proportional thickness of each of regions 1 and 2 are shown at about 80% and about 20%, respectively in that preferred embodiment. However, a wear product as disclosed herein may comprise the variation of the physical property of the protective material occurring at a depth of: 20 between about 50% and 95% of the thickness of the protective material; or between about 60% and 90% of the thickness of the protective material; or preferably as shown in figures 1 and 2, about 80% of the thickness of the protective material. In accordance with a preferred method of fabricating a wear product 25 comprising a composite ceramic material that provides a colour change for the variation in physical property, the following steps are followed: providing a metal mould held within a mechanical press; coloured alumina ceramic powder of known volume is added to the metal mould; 30 the coloured alumina powder surface is smoothed flat within the metal mould; white alumina ceramic powder is added to the smoothed surface to top up the mould; 10 mechanical press is engaged to compress alumina powder into shape; ceramic item is pressed as one piece with different coloured layers to form a green state item; green state ceramic item is ejected from metal mould; 5 green state ceramic item is fired in kiln to achieve sufficient physical and mechanical properties. While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s). This application is intended to cover any variations uses or 10 adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth. As the present invention may be embodied in several forms without 15 departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the appended claims. The described embodiments are to be considered in all respects as illustrative 20 only and not restrictive. Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention and appended claims. For example, whilst the present invention has utility and has been described in respect of wear products for lining machinery and equipment utilised in the 25 resources industry, an embodiment of the present invention may be applicable to more general products of industry, such as for example, a means of identifying and indicating wear of a road vehicle tyre where the variation in a physical property of protective wear material corresponds to the composite material comprising a tyre itself. In other embodiments envisaged, an application of the 30 present invention may comprise a chemical and/or electrical conductivity property changing to provide an in situ sensor a change of signal that provides an indication of wear to the user.

11 Therefore, the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced. In the following claims, means-plus-function clauses are intended to cover structures as performing the defined function and not only structural 5 equivalents, but also equivalent structures. For example, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface to secure wooden parts together, in the environment of fastening wooden parts, a nail and a screw are equivalent structures. 10 "Comprises/comprising" and "includes/including" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. Thus, unless the context clearly requires otherwise, throughout the description and the claims, the 15 words 'comprise', 'comprising', 'includes', 'including' and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

Claims (5)

1. A method of determining wear of a wear product in the form of discrete tiles, plates, cubes or the like, the wear product comprising protective material 5 and being adapted for lining a machine part utilised for handling raw materials, the method comprising the steps of: varying at least one physical property of the protective material as a function of depth from an outer exposed surface of the protective material; remotely sensing a change in the physical property as the outer exposed 10 surface propagates into the protective material in the course of use.

2. A method as claimed in claim 1 wherein the step of varying at least one physical property of the protective material comprises one of: a step change in physical property; 15 a gradual change in physical property; a graduated change in physical property, and; wherein the varying physical property comprises one or a combination of: visual appearance; audible perception; 20 mechanical vibration, or a change in colour of the protective material.

3. A wear product in the form of a discrete tile, plate, cube or the like, the wear product comprising a protective material and being adapted for lining a 25 machine part utilised for handling raw materials, the protective material comprising at least one physical property that varies as a function of depth from an outer exposed surface of the protective material, wherein as the outer exposed surface propagates into the protective material in the course of use a change in the physical property is remotely sensed to provide an indication of wear of the 30 wear product. 13

4. A wear product as claimed in claim 3 wherein the product is one of a wear plate, a wear tile, or a wear cube and the protective material comprises one or a combination of: a ceramic; 5 a metal; a rubber' a composite ceramic; a composite ceramic including metal or rubber. 10

5. A wear product as claims in claim 3 and substantially as herein described with reference to the accompanying drawings.