Influence of yttrium on microstructure and properties of Ni–Al alloy coatings prepared by laser cladding

Ni–Al alloy coatings with different Y additions are prepared on 45^# medium steel by laser cladding. The influence of Y contents on the microstructure and properties of Ni–Al alloy coatings is investigated using X-ray diffraction, scanning electron microscopy, electron probe microanalyzer, Vickers hardness tester, friction wear testing machine, and thermal analyzer. The results show that the cladding layers are mainly composed of NiAl dendrites, and the dendrites are gradually refined with the increase in Y additions. The purification effect of Y can effectively prevent Al₂O₃ oxide from forming. However, when the atomic percent of Y addition exceeds 1.5%, the extra Y addition will react with O to form Y₂O₃ oxide, even to form Al₅Y₃O₁₂ oxide, depending on the amount of Y added. The Y addition in a range of 1.5–3.5 at.% reduces the hardness and anti-attrition of cladding layer, but improves obviously its wear and oxidation resistances.     

Influence of high frequency pulse on electrode wear in micro-EDM

An electromagnetic coupling mathematical model is established by finite element method and is verified by the contrastive experiments of copper matrix Ni–TiN cylindrical coating electrode, copper electrode and Cu50W electrode. The wear mechanism of Ni–TiN/Cu composite electrode in the case of high-frequency pulse current is studied, and the influence of the fluctuation frequency of discharge current on electrode wear in micro-EDM is found out. Compared with the electrode made from homogeneous material, the high frequency electromagnetic properties of Ni–TiN composite layer can be used effectively to inhibit the effect of high frequency pulse on the electrode and improve the distribution trend of current density.     

Measuring Military Professionalism in Partner Nations: Guidance for Security Assistance Officials

The U.S. spends billions of dollars in its security cooperation program to develop “professional, accountable, and capable security forces” in other nations, part of a grand strategy to improve global stability and counter violent extremism. Despite its great investment in professionalizing foreign militaries, however, the U.S. has no functional definition of military professionalism – a term that until now has been considered too vague and multi-faceted to operationalize. In this article, the author seeks to remedy this oversight, drawing from twenty years of security cooperation fieldwork in Latin America and Africa, as well as a vigorous literature review, to define four important components of military professionalism: (1) formal military education and vocational training, (2) military subordination to elected civilian officials, (3) knowledge and practice of the law of armed conflict and human rights law, and (4) a clearly established program of professional military ethics. This article provides guidelines for U.S. and European officials who work with partner nations to develop more professional military forces and, in particular, for officials managing security assistance programs with developing countries.     

“Flectas non frangas”: revisiting early twenty-first century UK–US defense relations (2000–2005) after five years

Adopting the analytical framework of the established interpretive “schools” of Anglo-American relations, this article offers several reflections on UK–US defense relations as they occurred over the significant years of 2000–2005. During those years, trajectories were established on which UK–US defense relations continue to travel today and outcomes emerged which are still being navigated. This article concludes that the Latin phrase, “Flectas Non Frangas” (essentially translated as: “Bend not Break”), is the most appropriate to adopt to characterize the developments undergone in recent UK–US defense relations. Many historical and strategic lessons with contemporary relevance are drawn.     

《孙子兵法》“五德”思想对现代化武警警官素质修养的借鉴与启迪

古代《孙子兵法》要求为将之道必须具备“智”、“信”、“仁”、“勇”、“严”五德要素。新时期部队指挥员应当借鉴历史经验,努力提高自身素质修养,大力培育部队优良战斗作风,为履行新使命、新职责打下坚实基础。     

India’s Taliban Dilemma: To Contain or to Engage?

India’s Afghanistan policy in the 1990s is termed a zero-sum game of influence with Pakistan. New Delhi’s aversion to the pro-Pakistan Taliban regime is considered a marker of this rivalry. This paper revisits India’s approach towards Afghanistan and examines if New Delhi was necessarily averse to engaging with pro-Pakistan political factions during 1990s. Based on fresh primary interviews with former Indian policymakers, media archives, and official reports, the paper shows that India engaged with and accommodated pro-Pakistan factions after the Soviet withdrawal in 1989 until 1996. The Taliban’s rise to power in Kabul in September 1996 challenged India’s engage-with-all approach. Nonetheless, the decision to sever ties with the Taliban and to bolster anti-Taliban factions was highly debated in New Delhi. Many in India saw the Taliban as a militant Islamist force sponsored by Pakistan. For others, however, it was an ethno-nationalist movement representing Pashtun interests, and not necessarily under Islamabad’s control.     

Shifting power,preventive logic,and the response of the target: Germany,Russia, and the First World War

If a declining state has incentives for preventive war, the rising state should have incentives to delay a confrontation until it is stronger. We develop the theoretical paradox and examine the July 1914 crisis. Why did Russia, rising relative to Germany, not adopt a buying-time strategy? We argue that although most Russian leaders hoped to avoid a confrontation, they feared that the failure to support Serbia would lead to a loss of Russian credibility and a significant setback to Russia’s position in the Balkans, one that could not easily be reversed, even with Russia’s expected increase in relative military power.     

Homes for heroes? Assessing the impact of the UK’s Military Covenant

The British Military Covenant can be located in and from many sources and from 2011 onwards in primary legislation. This article argues that the provision of military housing amounts to an early test of how the military covenant is understood and used by those involved in defence policy, and those in the armed forces affected by it. It finds that housing was a prominent feature of how service personnel understood how they were valued, but was not explicitly understood as a covenant issue by those personnel or the officials in charge of the Defence Estates. We locate three reasons for this: (1) the covenant has been poorly translated from aspiration into policy practice, (2) the covenant is unevenly understood across its stakeholders which has the effect of generating disappointment through misaligned expectations, (3) those engaged in the reform process surrounding the Defence Infrastructure Organisation (DIO) saw the covenant as a means to energise reform. Ultimately housing was seen as a dry and technocratic business area and thus an issue ripe for being refracted through the covenant was ultimately left outside of its remit.     

Israel’s Security Nexus as Strategic Restraint: The Case of Iran 2009–2013

This article examines the debates in Israel between 2009 and 2013 over Iran’s nuclear programme as a reflection of a particular type of civil–military or civil–security relationship. It analyses how key actors within that relationship – particularly those with an intelligence background – engaged with media outlets in Israel and further afield to influence domestic and international opinion over how best to contain Iran’s nuclear ambitions. In so doing, it seeks to address one fundamental question: are governments in Jerusalem any longer the final arbiters over deciding what is in the national security interests of the State of Israel?     

Self-Defense Militias,Death Squads,and State Outsourcing of Violence in India and Turkey

What explains the variation in states’ nonstate partners in civil warfare? States often use nonstate actors to do what their regular military forces cannot do well – navigate the local population. Some of their nonstate partners are ordinary civilians, while others are battle-hardened fighters with a rebellious or criminal past. The choice of proxy carries serious implications for the patterns and effects of violence during civil war, human rights, and international security. This article is the first to disaggregate the nonstate counterinsurgents and offer an explanation for why and how states use each type. It brings together the politics of collaboration with the politics of exploitation. The article shows that the state’s use of nonstate proxies is shaped by the supply of willing collaborators, the state’s ability to exercise control over them, and the trade-offs underlying the use of the different types of nonstate actors. The empirical evidence used to support this argument comes from a novel, comparative study of Turkey’s counterinsurgency campaign against Kurdish separatists and India’s counterinsurgency against Kashmiri separatists. The original data were collected through fieldwork in the disputed territories of each country.