V-W Alloy Target Hardness Control for Coating Quality
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Solution Overview
Problem
V-Ti targets produced through pressure-sintering with a hot isostatic press can have local sites of low hardness, leading to surface irregularities and increased risk of abnormal discharge during arc ion plating, which affects the quality of hard coatings and tool reliability.
Innovation Solution
A V alloy target composed of V and W with a controlled Vickers hardness range of 340 to 750 HV and a variation of 20% or less, achieved through powder sintering methods like HIP, ensures a smooth surface and reduces the occurrence of droplet adhesion and abnormal discharge during film formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a V-Ti target is produced through pressure-sintering with a hot isostatic press, then the target can be manufactured with desired composition, but local sites with low hardness may be present leading to surface irregularities
Solution Approach 1:
The invention changes the compositional parameters by replacing Ti with W in the V alloy target. W has higher hardness and different sintering characteristics that prevent local soft spots. By adjusting the W content to 1-30 at%, the target achieves uniform hardness distribution while maintaining manufacturability through conventional pressure-sintering processes.
Solution Approach 2:
The invention creates a composite alloy system of V-W that combines the beneficial properties of both elements. V provides the base matrix with good ductility, while W disperses throughout to provide hardness and prevent local soft spots. This composite approach resolves the contradiction between ease of manufacture and surface uniformity.
2Strength
If a V alloy target with high hardness is used, then abrasion resistance of the coating is improved, but machine working becomes difficult and cutting tools may be damaged
Solution Approach 1:
The invention optimizes the W content parameter within a specific range (1-30 at%) to balance hardness and machinability. This controlled composition ensures the target has sufficient hardness for abrasion resistance while remaining workable with conventional cutting tools, avoiding the extreme hardness that would cause tool damage.
Solution Approach 2:
The invention creates a heterogeneous microstructure where W particles are distributed throughout the V matrix. The V matrix provides ductility for machinability, while the dispersed W particles provide localized hardness for abrasion resistance. This local quality distribution resolves the contradiction between overall hardness and ease of manufacture.
3Ease of manufacture
If a V alloy target with inconsistent hardness is used, then manufacturing is easier, but abnormal discharge may occur during arc ion plating and droplets may fly off and adhere to the workpiece
Solution Approach 1:
The invention changes the compositional parameter by using W instead of Ti, which fundamentally alters the hardness distribution characteristics. W forms a more uniform and stable hardness distribution during pressure-sintering, preventing the local soft spots that lead to surface irregularities and subsequent coating defects during arc ion plating.
Solution Approach 2:
The V-W composite alloy system provides inherent uniformity in hardness distribution due to the compatible sintering behavior and atomic size match between V and W. This composite structure ensures consistent material properties throughout the target, eliminating the hardness inconsistency that causes abnormal discharge and droplet formation during coating deposition.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The controlled Vickers hardness range in the V-W alloy target suppresses surface irregularities and abnormal discharge, enhancing the quality of hard coatings with improved abrasion resistance and reduced friction variation, while maintaining tool reliability and preventing damage to cutting tools.
Implementation Method 1
Arc ion plating, which is a type of ion plating method, is a method for forming a hard coating by instantaneously dissolving and ionizing a target as a raw material of the hard coating through arc discharge in a depressurized reaction gas atmosphere and causing the ions to adhere to the negative voltage applied workpiece.
Implementation Method 2
instantaneously dissolving and ionizing a target as a raw material of the hard coating through arc discharge
Implementation Method 3
a target used in arc ion plating is composed of a plate material with a desired composition that is similar to that of the hard coating to be obtained and is generally manufactured by a powder sintering method
Data Source
AI summary
Provided is a novel V alloy target, wherein the occurrence of irregularities on the surface of the target can be suppressed during the machining of the target, and the deposition of droplets on workpieces can be suppressed while the occurrence of abnormal discharge is suppressed during film formation. The V alloy target is composed of V and W, wherein the average value of Vickers hardness on an erosion surface is in the range of 340-750 HV, and the variation in Vickers hardness measured at 5 measurement points is 20% or less. Preferably, the V alloy target has a Vickers hardness in the range of 350-710 HV, and more preferably contains 10-50 at% of W with the remainder comprising V and inevitable impurities.