Effects of antiwear additives on the friction and wear of Si3N4/steel sliding contacts

Recent Advancements in Understanding of Growth and Properties of Antiwear Tribofilms Derived from Zinc Dialkyl Dithiophosphate Additives under Nanoscale Sliding Contacts

“…Nevertheless, this explanation falls short in elucidating tribofilm formation on a variety of nonferrous surfaces. Some studies proposed that the tribochemical reaction on nonferrous surfaces occurred due to ferrous counterface during rubbing; ,− yet, this notion complicated the understanding of the mechanism of tribofilm formation on nonferrous surfaces. Interestingly, observations of ZDDP tribofilm growth on nonferrous/nonferrous tribopairs despite the absence of Fe 3+ ions add disagreement to the governing HSAB reaction model.…”

“…Furthermore, the HSAB model appreciably explained the mechanism of formation of the ZDDP tribofilm on ferrous surfaces through the exchange of Zn 2+ (from the ZDDP molecule) and Fe 3+ (from the substrate) ions, followed by the interaction of the latter with the phosphates. Numerous studies have supported the HSAB model for tribofilm formation on a nonferrous surface, attributing its cause to the involvement of the ferrous counterface during rubbing. ,− However, the model maintained its ambiguity in explaining the growth of ZDDP tribofilm on nonferrous/nonferrous tribopairs. Some investigations on ceramic surfaces such as tungsten carbide or sapphire substrate showed that even under high contact stress, these surfaces exhibited neither any observable wear nor plastic deformation.…”

Recent Advancements in Understanding of Growth and Properties of Antiwear Tribofilms Derived from Zinc Dialkyl Dithiophosphate Additives under Nanoscale Sliding Contacts

“…Nevertheless, this explanation falls short in elucidating tribofilm formation on a variety of nonferrous surfaces. Some studies proposed that the tribochemical reaction on nonferrous surfaces occurred due to ferrous counterface during rubbing; ,− yet, this notion complicated the understanding of the mechanism of tribofilm formation on nonferrous surfaces. Interestingly, observations of ZDDP tribofilm growth on nonferrous/nonferrous tribopairs despite the absence of Fe 3+ ions add disagreement to the governing HSAB reaction model.…”

“…Furthermore, the HSAB model appreciably explained the mechanism of formation of the ZDDP tribofilm on ferrous surfaces through the exchange of Zn 2+ (from the ZDDP molecule) and Fe 3+ (from the substrate) ions, followed by the interaction of the latter with the phosphates. Numerous studies have supported the HSAB model for tribofilm formation on a nonferrous surface, attributing its cause to the involvement of the ferrous counterface during rubbing. ,− However, the model maintained its ambiguity in explaining the growth of ZDDP tribofilm on nonferrous/nonferrous tribopairs. Some investigations on ceramic surfaces such as tungsten carbide or sapphire substrate showed that even under high contact stress, these surfaces exhibited neither any observable wear nor plastic deformation.…”

ZDDP Tribofilm Formation on Non-Ferrous Surfaces

“…In addition, most studies on the behaviour of ZDDP with non-ferrous surfaces have been conducted using a non-ferrous on ferrous tribopair. These studies have reported presence of tribofilms on various nonferrous surfaces including Al-Si alloy, Si 3 N 4 , SiC, ZrO 2 and DLC coatings [10][11][12][13][14][15] and researchers have generally suggested that these tribofilms have been transferred from the ferrous counterface during rubbing. This possible transfer of tribofilm or of ferrous or ferric ions from ferrous surfaces complicates the understanding of reaction mechanism of tribofilm formation on non-ferrous surfaces.…”

Lubrication studies of head-disk interfaces in a controlled environment: Part 1: Effects of disk texture, lubricant thermal treatment and lubricant additive on the durability of the head-disk interface

“…It is well known that the tribochemical reactions of extreme-pressure (EP) additives in conventional industrial lubricants (hydrocarbon lubricants) are mainly caused by the high contact pressure between rubbing surfaces; the tribochemical reaction principles of the EP additives are just based on the high contact pressure, which prompts the tribochemical reaction between the active elements (sulphur, phosphorus, etc.) in EP additives and the active rubbing surfaces (metallic materials), and then the EP tribochemical film formed on rubbing surface can protect the surface from wear [13,14]. However, at the interface of the slider and laser-textured disk, the higher contact pressure only prompted the tribochemical reaction (decomposition) of the Z-Dol lubricant; no possible wear protection film could be formed with the decomposition of Z-Dol.…”

Recent Advancements in Understanding of Growth and Properties of Antiwear Tribofilms Derived from Zinc Dialkyl Dithiophosphate Additives under Nanoscale Sliding Contacts

“…Nevertheless, this explanation falls short in elucidating tribofilm formation on a variety of nonferrous surfaces. Some studies proposed that the tribochemical reaction on nonferrous surfaces occurred due to ferrous counterface during rubbing; ,− yet, this notion complicated the understanding of the mechanism of tribofilm formation on nonferrous surfaces. Interestingly, observations of ZDDP tribofilm growth on nonferrous/nonferrous tribopairs despite the absence of Fe 3+ ions add disagreement to the governing HSAB reaction model.…”

“…Furthermore, the HSAB model appreciably explained the mechanism of formation of the ZDDP tribofilm on ferrous surfaces through the exchange of Zn 2+ (from the ZDDP molecule) and Fe 3+ (from the substrate) ions, followed by the interaction of the latter with the phosphates. Numerous studies have supported the HSAB model for tribofilm formation on a nonferrous surface, attributing its cause to the involvement of the ferrous counterface during rubbing. ,− However, the model maintained its ambiguity in explaining the growth of ZDDP tribofilm on nonferrous/nonferrous tribopairs. Some investigations on ceramic surfaces such as tungsten carbide or sapphire substrate showed that even under high contact stress, these surfaces exhibited neither any observable wear nor plastic deformation.…”

ZDDP Tribofilm Formation on Non-Ferrous Surfaces

“…In addition, most studies on the behaviour of ZDDP with non-ferrous surfaces have been conducted using a non-ferrous on ferrous tribopair. These studies have reported presence of tribofilms on various nonferrous surfaces including Al-Si alloy, Si 3 N 4 , SiC, ZrO 2 and DLC coatings [10][11][12][13][14][15] and researchers have generally suggested that these tribofilms have been transferred from the ferrous counterface during rubbing. This possible transfer of tribofilm or of ferrous or ferric ions from ferrous surfaces complicates the understanding of reaction mechanism of tribofilm formation on non-ferrous surfaces.…”

Lubrication studies of head-disk interfaces in a controlled environment: Part 1: Effects of disk texture, lubricant thermal treatment and lubricant additive on the durability of the head-disk interface

“…It is well known that the tribochemical reactions of extreme-pressure (EP) additives in conventional industrial lubricants (hydrocarbon lubricants) are mainly caused by the high contact pressure between rubbing surfaces; the tribochemical reaction principles of the EP additives are just based on the high contact pressure, which prompts the tribochemical reaction between the active elements (sulphur, phosphorus, etc.) in EP additives and the active rubbing surfaces (metallic materials), and then the EP tribochemical film formed on rubbing surface can protect the surface from wear [13,14]. However, at the interface of the slider and laser-textured disk, the higher contact pressure only prompted the tribochemical reaction (decomposition) of the Z-Dol lubricant; no possible wear protection film could be formed with the decomposition of Z-Dol.…”

Recent Advancements in Understanding of Growth and Properties of Antiwear Tribofilms Derived from Zinc Dialkyl Dithiophosphate Additives under Nanoscale Sliding Contacts

“…Nevertheless, this explanation falls short in elucidating tribofilm formation on a variety of nonferrous surfaces. Some studies proposed that the tribochemical reaction on nonferrous surfaces occurred due to ferrous counterface during rubbing; ,− yet, this notion complicated the understanding of the mechanism of tribofilm formation on nonferrous surfaces. Interestingly, observations of ZDDP tribofilm growth on nonferrous/nonferrous tribopairs despite the absence of Fe 3+ ions add disagreement to the governing HSAB reaction model.…”

“…Furthermore, the HSAB model appreciably explained the mechanism of formation of the ZDDP tribofilm on ferrous surfaces through the exchange of Zn 2+ (from the ZDDP molecule) and Fe 3+ (from the substrate) ions, followed by the interaction of the latter with the phosphates. Numerous studies have supported the HSAB model for tribofilm formation on a nonferrous surface, attributing its cause to the involvement of the ferrous counterface during rubbing. ,− However, the model maintained its ambiguity in explaining the growth of ZDDP tribofilm on nonferrous/nonferrous tribopairs. Some investigations on ceramic surfaces such as tungsten carbide or sapphire substrate showed that even under high contact stress, these surfaces exhibited neither any observable wear nor plastic deformation.…”

ZDDP Tribofilm Formation on Non-Ferrous Surfaces

“…In addition, most studies on the behaviour of ZDDP with non-ferrous surfaces have been conducted using a non-ferrous on ferrous tribopair. These studies have reported presence of tribofilms on various nonferrous surfaces including Al-Si alloy, Si 3 N 4 , SiC, ZrO 2 and DLC coatings [10][11][12][13][14][15] and researchers have generally suggested that these tribofilms have been transferred from the ferrous counterface during rubbing. This possible transfer of tribofilm or of ferrous or ferric ions from ferrous surfaces complicates the understanding of reaction mechanism of tribofilm formation on non-ferrous surfaces.…”

Lubrication studies of head-disk interfaces in a controlled environment: Part 1: Effects of disk texture, lubricant thermal treatment and lubricant additive on the durability of the head-disk interface

“…It is well known that the tribochemical reactions of extreme-pressure (EP) additives in conventional industrial lubricants (hydrocarbon lubricants) are mainly caused by the high contact pressure between rubbing surfaces; the tribochemical reaction principles of the EP additives are just based on the high contact pressure, which prompts the tribochemical reaction between the active elements (sulphur, phosphorus, etc.) in EP additives and the active rubbing surfaces (metallic materials), and then the EP tribochemical film formed on rubbing surface can protect the surface from wear [13,14]. However, at the interface of the slider and laser-textured disk, the higher contact pressure only prompted the tribochemical reaction (decomposition) of the Z-Dol lubricant; no possible wear protection film could be formed with the decomposition of Z-Dol.…”